LEASE

 WINTER STREET OFFICE PARK
                             245 - 265 WINTER STREET
                             WALTHAM, MASSACHUSETTS
                                      LEASE
                                   dated as of
                                   MAY_, 1996

  ARTICLE I
 
1.1 REFERENCE DATA

  Subjects  referred  to each  reference  in this Lease to any of the  following
  subjects shall be construed to incorporate the data stated for that subject in
  this Article:

  LANDLORD: K/B Fund III

  LANDLORD'S ORIGINAL ADDRESS:       c/o Koll Management Services, Inc.
                                     60 State Street
                                     Boston, MA 02109

  LANDLORD'S CONSTRUCTION REPRESENTATIVE: Robert Tagliamonte

  TENANT: The Software Developer's Company, Inc.

  TENANT'S ORIGINAL ADDRESS:   90 Industrial Park Road
                               Hingham, MA 02043

  TENANT'S CONSTRUCTION REPRESENTATIVE:
                                       -------------------------------
  TENANT'S FINAL PLANS DATE: Not Applicable

  SCHEDULED TERM COMMENCEMENT DATE: June 1, 1996

  TENANT'S SPACE:        5,760 Rentable Square Feet on the First (1st) Floor
                         of Building 245 as shown on Exhibit E
                         attached hereto.

  TERM: Sixty (60) full calendar months

  ANNUAL FIXED RENT:           YEAR          ANNUAL                    MONTHLY
                               ----          ------                    -------
                               1             $95,040.00                $7,920.00
                               2 - 5         $100,800.00               $8,400.00

  ANNUAL ELECTRICITY CHARGE: $1.00

  TENANT'S TAX BASE: Tax Year 1996 (July 1, 1995 - June 30, 1996)

  TENANT'S OPERATING EXPENSE BASE:      Calendar Year 1996 (January 1,
                                        1996 - December 31, 1996)

                   KBFIII/SOFTWARE DEVELOPER's COMPANY/5.1.96

RENTABLE FLOOR AREA OF THE BUILDING:    89,305 Rentable Square Feet
                                        with respect to 245 Winter
                                        Street.

PERMITTED USES: Office Purposes

PUBLIC LIABILITY INSURANCE:             Bodily Injury - $5,000,000.00
                                        Property Damage - $5,000,000.00

SECURITY DEPOSIT: $16,885.00

1.2 EXHIBITS. There are incorporated as a part of this Lease:

        EXHIBIT A - Description of Lot
        EXHIBIT B - Construction
        EXHIBIT C - Tenant Plan Requirements
        EXHIBIT D - Landlord's Services
        EXHIBIT E - Floor Plan
        EXHIBIT F - Required Tenant Work General Conditions

1.3 TABLES OF ARTICLES AND SECTIONS

ARTICLE I - REFERENCE DATA
  1.1      Subjects Referred To
  1.2      Exhibits
  1.3      Table of Articles and Sections

ARTICLE II - PREMISES, TERM AND RENT
  2.1      The Premises
  2.2      Rights to Use Common Facilities
  2.3      Landlord's Reservations
  2.4      Commencement of Term
  2.5      Monthly Fixed Rent Payments
  2.6      Adjustment for Operating Expenses
  2.7      Adjustment for Real Estate Taxes
  2.8      Due Date of Additional Payments; No Offsets
  2.9      Security Deposit

ARTICLE III - ALTERATIONS AND CONSTRUCTION
  3.1      Alterations  and  Additions  by Tenant
  3.2      Real Estate Taxes on Leasehold Improvements
  3.3      Landlord's Right to Make Alterations 

ARTICLE IV - LANDLORD'S  COVENANTS;  INTERRUPTIONS  AND DELAYS
  4.1      Services  Furnished by Landlord
  4.2      Additional  Services  Available  to Tenant
  4.3      Additional  Air  Conditioning  Equipment
  4.4      Roof, Exterior Wall, Floor Slab and Common Facility Repair
  4.5      Door Signs and Directory
  4.6      Quiet Enjoyment

                   KBFIII/SOFTWARE DEVELOPER's COMPANY/5. 1.96

ARTICLE V - TENANT'S COVENANTS
   5.1     Payments
   5.2     Repair and Yield Up
   5.3     Use
   5.4     Obstructions, Items Visible from Exterior; Rules and Regulations
   5.5     Safety Appliances
   5.6     Assignment; Sublease
   5.7     Indemnity; Insurance
   5.8     Personal Property at Tenant's Risk
   5.9     Right of Entry
   5.10    Floor Load; Prevention of Vibration and Noise
   5.11    Personal Property Taxes
   5.12    Payment of Litigation Expenses
   5.13    Compliance with Insurance Regulations
   5.14    Subject to Applicable Law
   5.15    Fines and Penalties

ARTICLE VI -  CASUALTY  AND  TAKING
   6.1     Termination  or  Restoration;  Rent Adjustment 
   6.2     Eminent Domain  Damages  Reserved
   6.3     Temporary  Taking

ARTICLE VII - DEFAULT
   7.1     Events of Default 
   7.2     Damages 

ARTICLE VIII - MISCELLANEOUS
   8.1     Computation of Rentable Floor Areas
   8.2     Notice of Lease; Consent of Approval; Notices; Bind and Inure
   8.3     Landlord's Failure to Enforce
   8.4     Acceptance of Partial Payments of Rent; Delivery of Keys
   8.5     Cumulative Remedies
   8.6     Partial Invalidity
   8.7     Self-Help
   8.8     Tenant's Estoppel Certificate
   8.9     Waiver of Subrogation
   8.10    All Agreements Contained
   8.11    Brokerage
   8.12    Submission Not an Option
   8.13    Applicable Law
   8.14    Waiver of Jury Trial
   8.15    Holdover
   8.16    Arbitration
   8.17    Inability to Perform
   8.18    Exculpatory Clause
   8.19    Parties Bound - Seisin of Title

ARTICLE IX - RIGHTS OF PARTIES HOLDING PRIOR INTERESTS
   9.1     Lease Subordinate
   9.2     Rights of Holder of Mortgage to Notice  of  Defaults  Landlords  and 
           to Cure Same.

                   KBFIII/SOFTWARE DEVELOPER's COMPANY/5.1.96

                                   ARTICLE II

                             PREMISES, TERM AND RENT

2.1 THE PREMISES

Landlord hereby leases to Tenant and Tenant hereby hires from Landlord  Tenant's
Space in the  Building.  The demise of the  Premises  does not include  faces of
exterior  walls,  the common  stairways and  stairwells,  elevators and elevator
shafts,  fan rooms,  electric and telephone  closets,  janitor closets,  freight
elevator vestibules,  and pipe, ducts, conduits,  wires and appurtenant fixtures
serving  exclusively  or in common other parts of the Building,  and if Tenant's
Space  includes less than the entire  rentable area of any floor,  excluding the
common corridors,  elevator lobbies and toilets located on such floor.  Tenant's
Space  with  such  exclusions  is  hereinafter  referred  to as the  "PREMISES".
Landlord  reserves the right,  at its own cost and expense,  to require  Tenant,
upon not less than thirty (30) days' notice, to relocate its Premises  elsewhere
in the Building to an area of substantially  equivalent  size,  construction and
finish as designated by Landlord.  Any dispute between the parties as to whether
the area designated by Landlord is "substantially equivalent" shall be submitted
to  arbitration  pursuant to Section 8.16 hereof The term  "Building"  means the
building in which the Premises  are  located,  and the term "Lot" means all, and
also any  part  of,  the land  described  in  Exhibit  A in whole or in part and
subject  to  minor  adjustments  of the lot  boundaries.  "PROPERTY"  means  the
Building  and  Lot  and  other  improvements  on  the  Lot  including,   without
limitation, other buildings on the Lot.

2.2 RIGHTS TO USE COMMON FACILITIES

Tenant shall have,  as  appurtenant  to the  Premises,  rights to use in common,
subject to reasonable rules of general  applicability to tenants of the Building
from time to time made by  Landlord  of which  Tenant is given  notice:  (a) the
common  lobbies,  corridors,  stairways,  elevators and loading  platform of the
Building,  and the pipes,  ducts,  conduits,  wires and  appurtenant  meters and
equipment  serving the Premises in common with others,  (b) common  walkways and
driveways  necessary  for access to the Building,  (c) if the Premises  included
less than the entire rentable area of any floor,  the common toilets,  corridors
and  elevator  lobbies  of such  floor  and (d) the  common  parking  facilities
adjacent  to the  Building  (Tenant  hereby  acknowledging  that (i)  parking is
available on a first-come,  first-served basis only, (ii) Tenant, its employees,
agents,  contractors  and  invitees  shall not be entitled to use at any time in
excess of 3 parking spaces per 1,000 square feet of Rentable  Square Feet of the
Premises,  (iii)  Landlord  shall have the right to designate  exclusive  and/or
reserved  parking  areas,  and (iv)  Landlord  shall have the right to institute
measures  reasonably   necessary  to  enforce  the  foregoing);   and  no  other
appurtenant rights or easements.

2.3 LANDLORD'S RESERVATIONS

Landlord reserves the right from time to time, without unreasonable interference
with Tenant's use: (a) to install, use, maintain,  repair,  replace and relocate
for service to the Premises and other parts of the Building,  or either,  pipes,
ducts,  conduits,  wires  and  appurtenant  fixtures,  wherever  located  in the
Premises or Building,  and (b) to alter or relocate  any other common  facility,
provided   that   substitutions   are   substantially   equivalent   or  better.
Installations,  replacements and  reallocations  referred to in clause (a) above
shall be located so far as practicable in the central core area of the Building,
above ceiling  surfaces,  below floor surfaces or within  perimeter walls of the
Premises.

                   KBFIII/SOFTWARE DEVELOPER's COMPANY/5. 1.96

2.4 COMMENCEMENT OF TERM

Tenant  shall have and hold the  Premises  for a period  commencing  on the date
("TERM  COMMENCEMENT  DATE")  which  is  the  earlier  of  (a)  the  Substantial
Completion Date, as defined in Exhibit B to the Lease, or (b) that date on which
Tenant commences occupancy of any portion of the Premises for the Permitted Uses
and shall expire as of the Termination Date.

If Landlord shall be unable to give  possession of the Premises on the Scheduled
Term  Commencement  Date because the Premises  are not  completed  and ready for
occupancy,  or due to the holding over or retention of  possession of any tenant
or occupant,  or if repairs,  improvements  or decorations of the Premises or of
the Building are not completed,  or for any other reason,  Landlord shall not be
subject to any liability for failure to give  possession on said date, nor shall
such failure affect the continuing validity of this Lease.

2.5 MONTHLY FIXED RENT PAYMENTS

Tenant shall pay, without notice or demand,  monthly installments of 1/12 of (a)
the Annual Fixed Rent, and (b) a charge ("ANNUAL  ELECTRICITY  CHARGE") equal to
$1.00 per annum for each square foot of Rentable  Floor Area of the Premises for
tenant electricity, as described in paragraph VI (A) of Exhibit D, in advance on
the first day of each month for each full  calendar  month of the Term,  and the
corresponding  fraction of said amounts for any fraction of a calendar  month at
the beginning or end of the Term.  Notwithstanding the provisions hereof, Tenant
shall pay the first monthly installment of Annual Fixed Rent on the execution of
this Lease.

Rental  and any other  sums due  hereunder  not paid by the date due shall  bear
interest  for each  month or  fraction  thereof  from  the due date  until  paid
computed at the annual  rate of two (2)  percentage  points  over the  so-called
prime rate as published in The Wall Street Journal,  or at any applicable lesser
maximum legally permissible rate for debts of this nature.

In  addition,  should  Tenant fail to pay when due rental and any other sums due
hereunder,   Tenant   acknowledges   that   Landlord   will   incur   additional
administrative  expenses  which are difficult to determine.  Therefore,  in such
event,  Landlord may assess against Tenant,  from and after the tenth (10th) day
following the date on which any sum shall be due and payable, a late payment fee
equal to five (5%) of the sum due from Tenant to Landlord.

2.5.1. RENT REDUCTION

Provided  Tenant has not been in default  during the Term,  and there  exists no
condition which with the passage of time or the giving of notice, or both, would
constitute a default under this Lease,  Landlord shall waive Tenant's obligation
to pay Monthly Fixed Rent for the 11th and 12th calendar months during the Term.
If Tenant subsequently defaults during the Term, then in addition to and without
limiting  Landlord's  other  remedies,  Tenant  shall pay to Landlord an  amount
equal the Fixed Monthly Rent payments which were hereby waived.

                   KBFIII/SOFTWARE DEVELOPER's COMPANY/5. 1.96

2.6 ADJUSTMENT FOR OPERATING EXPENSES

A. Terms used herein are defined as follows:

(a)  "OPERATING  YEAR" shall mean any 12 month  period  elected by Landlord  for
operating purposes. Landlord's current Operating Year commences on January 1, of
each year.  If Landlord  should elect to change said  Operating  Year,  Landlord
shall notify Tenant thereof, and all calculations required to be made at the end
of a Operating Year shall be made and proportioned accordingly.

(b)  "OPERATING  EXPENSES FOR THE  PROPERTY"  means the cost of operation of the
Property  which  shall  exclude  costs of special  services  rendered to tenants
(including  Tenant)  for which a separate  charge is made,  and items of expense
referred to in Section 2.7 hereof, but shall include,  without  limitation,  the
following:   Premiums  for  insurance  carried  with  respect  to  the  Property
(including  insurance  against  loss  in  case  of  fire  or  casualty,  monthly
installments of Annual Fixed Rent and any additional rent which may be due under
this Lease and other leases of space in the Building  and, if there be any first
mortgage of the  Property,  including  such  insurance as may be required by the
holder of such first mortgage);  compensation and all fringe benefits,  Worker's
Compensation  Insurance  premiums and payroll taxes paid to, for or with respect
to all persons engaged in the operating, repairing,  maintaining, or cleaning of
the  Building or Lot;  steam,  water,  sewer,  gas, oil and  telephone  charges;
electricity  provided to the Building and to the Premises;  cost of building and
cleaning   supplies   and   equipment;   related   equipment,   facilities   and
appurtenances, elevators, cooling and heating equipment, provided, however, that
with  respect  to the  replacement  of any  capital  items or the  making of any
capital  expenditures  (collectively  called "capital  expenditures")  the total
amount  of  which is not  properly  incredible  in  Operating  Expenses  for the
Operating  Year in which they were made,  there shall be  included in  Operating
Expenses for each Operating Year in which and after such capital  expenditure is
made the annual  charge-off of such capital  expenditure.  The annual charge-off
shall be determined by (i) dividing the original cost of the capital expenditure
by the  number  of years of  useful  life  thereof.  The  useful  life  shall be
reasonably determined by Landlord;  and (ii) adding to such quotient an interest
factor  computed on the  unamortized  balance of such capital  expenditure at an
annual  rate of either one  percentage  point over the AA Bond rate  [Standard &
Poor's corporate composite or, if unavailable, it equivalent] as reported in the
financial  press at the time the capital  expenditure is made or, if the capital
item is  acquired  through  third-party  financing,  then the actual  [including
fluctuating]  rate paid by Landlord in financing the acquisition of such capital
item. Provided,  further,  that if Landlord reasonably concludes on the basis of
engineering  estimates that a particular capital expenditure will effect savings
in  Operating  Expenses  for  the  Property,   including,   without  limitation,
energy-related  costs,  and that such annual  projected  savings will exceed the
annual charge-off of capital expenditure computed as aforesaid, then and in such
events, the annual charge-off shall be determined by dividing the amount of such
capital  expenditure  by the number of years over which the projected  amount of
such savings shall fully amortize the cost of such capital item or the amount of
such capital expenditure;  and by adding the interest factor, as aforesaid; cost
of  maintenance,  cleaning  and  repairs,  cost  of  snow  removal  and  care of
landscaping;  payments under service  contracts with independent  contractors or
subsidiaries or affiliates of Landlord;  management fees; and all other expenses
paid in connection with the operation,  repair,  cleaning and maintenance of the
Building, Lot and Property.

(c) If during all or part of any  Operating  Year,  Landlord  is  providing  any
service or furnishing  any item to less than 100% of the Rentable  Floor Area of
the Property  (the cost of which  service or item would  otherwise  constitute a
part of  Operating  Expenses  for the  Property)  on account of (a) any rentable
portion of the Property not being occupied or

                   KBFIII/SOFTWARE DEVELOPER's COMPANY/5.1.96

leased,  (b) such item not being required or desired by a tenant, (c) any tenant
itself  obtaining  or  providing  such item,  or (d) any other  reason,  whether
similar or  dissimilar  to  the  foregoing;  then,  Operating  Expenses  for the
Property  shall be deemed to be increased  by an amount equal to the  additional
costs and expenses which would  reasonably have been incurred during such period
by Landlord if it had performed or furnished such item to 100% of the Property.

(d) "OPERATING EXPENSES ALLOCABLE TO THE PREMISES",  as may be adjusted pursuant
to  Subparagraph  (c) hereof,  shall mean the same  proportion  of the Operating
Expenses for the Property  which are allocable to the Building,  as  hereinafter
defined,  as the  Rentable  Floor Area of Tenant's  Space bears to the  Rentable
Floor Area of the Building  actually  leased on an average annual basis for said
Operating  Year. The Operating  Expenses for the Property which are allocable to
the Building shall be (i) those Operating  Expenses  attributable  solely to the
Building, plus (ii) the same proportion of those Operating Expenses attributable
to the portions of the Property other than the buildings thereon as the Rentable
Floor Area of the Building bears to the Rentable Floor Area of the Property, all
as same may be determined and equitably adjusted by Landlord.

(e) The "STATEMENT" shall mean a statement rendered to Tenant by Landlord within
90 days or as soon  thereafter  as  reasonably  possible  after  the end of each
Operating Year, provided Landlord's failure to render such Statement within such
period shall not limit Tenant's  obligations to make any required  payments when
the Statement is issued. The Statement shall be in reasonable detail,  certified
by Landlord's representative,  and show the Operating Expenses for the Property,
the Operating Expenses Allocable to the Premises, amounts already paid by Tenant
for Operating Expenses Allocable to the Premises  (including  Tenant's Operating
Expense  Base hereof and amounts paid  pursuant to part C of this Section  2.6),
and the amount of Operating  Expenses  Allocable to the Premises  remaining  due
from or overpaid by Tenant for the Operating Year or fraction thereof covered by
the Statement with appropriate prorations for fractional years.

B.  If with  respect  to any  Operating  Year of the  Term,  Operating  Expenses
Allocable to the Premises  exceed  Tenant's  Operating  Expense Base then Tenant
shall  pay to  Landlord  as  additional  rent the  amount of such  excess.  Such
payments  shall be made at the times and in the manner  hereinafter  provided in
this Section 2.6. Appropriate  prorations shall be made for those periods at the
beginning or end of the Term which are less than a full Operating Year.

Within 30 days after the date of delivery of such Statement, Tenant shall pay to
Landlord or Landlord  shall pay to Tenant as the case may be, the balance of the
amounts,  if any,  required to be paid pursuant to the above  provisions of this
Section 2.6,  except that Landlord may at its option credit any amounts due from
it to Tenant against  monthly  installments of Annual Fixed Rent next thereafter
coming due.

C.  Commencing  on the first day of the first month  following  the  delivery to
Tenant of the  Statement  referred  to above and on the first day of each  month
thereafter until delivery to Tenant of the next such Statement, Tenant shall pay
to Landlord,  on account of Tenant's  share of  increases in Operating  Expenses
Allocable to the Premises anticipated by Landlord for the then current Operating
Year,  1/12th of the  difference  between  Operating  Expenses  Allocable to the
Premises  calculated  by  Landlord  on the  basis of the most  recent  Operating
Expense  data or budget  available  from time to time,  and  Tenant's  Operating
Expense Base.

                   KBFIII/SOFTWARE DEVELOPER's COMPANY/5.1.96

2.7 ADJUSTMENTS FOR REAL ESTATE TAXES

Terms used herein are defined as follows:

(a) "TAX YEAR" means the  twelve-month  period beginning July 1 each year during
the Term or if the appropriate governmental tax fiscal period shall begin on any
date other than July 1, such other date.

(b) "TAX EXPENSES  ALLOCABLE TO THE PREMISES"  shall mean the same proportion of
the Landlord's Tax Expenses which are allocable to the Building,  as hereinafter
defined,  as the  Rentable  Floor Area of Tenant's  Space bears to the  Rentable
Floor Area of the Building  actually  leased on an average annual basis for said
Tax Year.  The Landlord's Tax Expenses which are allocable to the Building shall
be (i) those Tax Expenses  attributable  solely to the  Building,  plus (ii) the
same  proportion  of those Tax  Expenses  attributable  to the  portions  of the
Property  other than the  buildings  thereon as the  Rentable  Floor Area of the
Building bears to the Rentable Floor Area of the Property  actually leased on an
average  annual  basis  for said Tax  Year,  all as same may be  determined  and
equitably adjusted by Landlord.

(c)  "LANDLORD'S  TAX EXPENSES" with respect to any Tax Year means the aggregate
Real Estate Taxes on the Property with respect to that Tax Year,  reduced by any
abatements actually received with respect to that Tax Year.

(d) "REAL  ESTATE  TAXES"  means all taxes,  levies,  betterments,  and  special
assessments of every kind and nature assessed by National,  State,  Municipal or
by any other  governmental  authority on the Lot or the Building or the Property
which the  Landlord  shall become  obligated to pay because of or in  connection
with the  ownership,  leasing,  operating,  use or  occupancy  of the  Lot,  the
Building,  and the Property or based upon rentals  derived  therefrom;  charges,
fees and assessments for transit,  housing,  police,  fire or other governmental
services or purported benefits to the Building; service or user payments in lieu
of taxes; and reasonable expenses of any proceedings for abatement of taxes. The
amount of special taxes or special  assessments  to be included shall be limited
to the  amount  of the  installment  (plus  any  interest,  other  than  penalty
interest, payable therein) of such special tax or special assessment required to
be paid  during the year in  respect  of which such taxes are being  determined.
There  shall be  excluded  from  such  taxes  all  income,  estate,  succession,
inheritance and transfer taxes;  provided,  however,  that if at any time during
the Term the present  system of ad valorem tax of real property shall be changed
so that in lieu of or in addition to the whole or any part of the ad valorem tax
on real  property,  there shall be assessed on Landlord a capital  levy or other
tax on the gross rents received with respect to the Lot or Building or Property,
or a federal, state, county, municipal, or other local income, franchise, excise
or similar tax,  assessment,  levy or charge (distinct from any now in effect in
the  jurisdiction  in which the  Property is located)  measured by or based,  in
whole or in part,  upon any such  gross  rents,  than any and all of such  taxes
shall be  included  within the term "REAL  ESTATE  TAXES" but only to the extent
that the same would be payable if the Lot,  Building or  Property  were the only
property of Landlord.

If with  respect  to any Tax Year of the Term,  Tax  Expenses  Allocable  to the
Premises  exceed  Tenant's  Tax  Base,  then  Tenant  shall pay to  Landlord  as
additional  rent the amount of such excess.  Such payments  shall be made at the
times and in the manner  hereinafter  provided in this Section 2.7.  Appropriate
prorations  shall be made for those  periods at the beginning or end of the Term
which  are  less  than a full  Tax  Year.  Within  ninety  (90)  days or as soon
thereafter  as  reasonably  possible  after  the end of such  first  Tax Year or
fraction  thereof at the beginning of the Term, and of each  succeeding Tax Year
during the Term and within ninety (90) days or as soon  thereafter as reasonably
possible after lease termination

                   KBFIII/SOFTWARE DEVELOPER's COMPANY/5.1.96

  (provided Landlord's failure to render such statement within such period shall
  not  limit  Tenant's  obligations  to make  any  required  payments  when  the
  statement  is  issued),  Landlord  shall  render  to  Tenant  a  statement  in
  reasonable  detail certified by a  representative  of Landlord showing for the
  preceding Tax Year or fraction  thereof,  as the case may be,  Landlord's  Tax
  Expenses for the Property, and Tax Expenses Allocable to the Premises.

  Commencing  on the first day of the first  month  following  the  delivery  to
  Tenant of the  statement  referred to above and on the first day of each month
  thereafter  until delivery to Tenant of the next such statement,  Tenant shall
  pay to Landlord, on account toward Tenant's share of increases in Tax Expenses
  Allocable to the Premises anticipated for the then current Tax Year, 1/12th of
  the total  amount of Tax  Expenses  Allocable  to the Premises as shown on the
  most recent such statement  delivered to Tenant. The statements to be rendered
  to Tenant referred to above shall also show for the preceding Tax Year amounts
  of Real Estate  Taxes  already paid by Tenant on account for such year and the
  amount  of Tax  Expenses  Allocable  to the  Premises  remaining  due  from or
  overpaid  by  Tenant  for the Tax  Year or  fraction  thereof  covered  by the
  statement. Within 30 days after the date of delivery of such statement, Tenant
  shall pay to Landlord or Landlord  shall pay to Tenant as the case may be, the
  balance of the  amounts,  if any,  required  to be paid  pursuant to the above
  provisions of this Section 2.7,  except that Landlord may at its option credit
  any amounts due from it to Tenant against monthly installments of Annual Fixed
  Rent next thereafter coming due.

  To the extent that Real Estate Taxes shall be payable to the taxing  authority
  in installments for periods less than a Tax Year, the foregoing  statement may
  be rendered and payments made on account of such  installments with respect to
  such periods rather than with respect to such full Tax Year.

  2.8 DUE DATE, ADDITIONAL RENT; NO OFFSETS

  Except as otherwise  specifically provided herein, all sums, amounts, items or
  charges  payable by Tenant to Landlord under this Lease shall be considered as
  additional  rent,  and shall be paid by Tenant to Landlord on the first day of
  the month  following the date on which Landlord  notifies Tenant of the amount
  payable or on the tenth day after the giving of such notice,  whichever  shall
  be later.

  Any  such  notice  shall  specify  in  reasonable  detail  the  basis  of such
  additional rent. Annual Fixed Rent and additional rent shall be paid by Tenant
  to Landlord without offset or deduction.

  2.9 SECURITY DEPOSIT

  Contemporaneously  with the  execution  and  delivery of this Lease by Tenant,
  Tenant shall pay to Landlord,  in immediately  available  funds,  the Security
  Deposit, which shall be held by Landlord without liability for interest and as
  security for the  performance by Tenant of its  obligations  under this Lease.
  The Security  Deposit is not an advance  payment of Rent or a measure or limit
  of Landlord's  damages upon an Event of Default (as defined  below).  Landlord
  may, from time to time and without prejudice to any other remedy, use all or a
  part of the  Security  Deposit  to perform  any  obligation  which  Tenant was
  obligated, but failed, to perform hereunder. Following any such application of
  the  Security  Deposit,  Tenant  shall pay to Landlord on demand the amount so
  applied in order to restore  the  Security  Deposit  to its  original  amount.
  Within thirty (30) days of Landlord's receipt of Tenant's request given at any
  time after the Term ends, provided Tenant has performed all of its obligations
  hereunder, Landlord shall return to Tenant the balance of the Security Deposit
  not  applied  to satisfy  Tenant's  obligations.  If  Landlord  transfers  its
  interest in the

                   KBFIII/SOFTWARE DEVELOPER's COMPANY/5.1.96

Premises,  then Landlord may assign the Security  Deposit to the  transferee and
Landlord  thereafter  shall  have no  further  liability  for the  return of the
Security Deposit.

                                   ARTICLE III
 
                      TENANT ALTERATIONS AND CONSTRUCTION

3.1 Alterations and Additions by Tenant

(a) This  Section 3.1 shall apply  before and during the Term.  Tenant shall not
make alterations and additions to Tenant's Space except in accordance with plans
and  specifications  and a time schedule  therefor first approved by Landlord in
writing.  All  alterations and additions to Tenant's Space shall equal or exceed
the  specifications  and  quantities  provided  in Exhibit D. No  amendments  or
additions to Tenant's  approved  plans shall be made  without the prior  written
consent of Landlord.  Landlord shall not be deemed  unreasonable for withholding
approval of any  alterations or additions  which (a) involve or might affect any
structural or exterior  element of the Building,  any area or element outside of
the  Premises,  or any  facility  serving any area of the  Building  outside the
Premises,  or (b) will delay  completion of the Premises or Building or (c) will
require  unusual  expense to readapt the Premises to normal  office use on Lease
termination or increase the cost of construction or of insurance or taxes on the
Building or of the services  called for by Section 4.1 unless Tenant first gives
assurance  acceptable  to Landlord for payment of such  increased  cost and that
such  readaptation  will be made prior to such  termination  without  expense to
Landlord.

(b) All alterations and additions shall be part of the Building unless and until
Landlord  shall specify the same for removal  pursuant to Section 5.2.  Landlord
may elect to require Tenant at the expiration or sooner  termination of the term
of this Lease to restore the  Premises to  substantially  the same  condition as
existed at the Term Commencement  Date. Upon Tenant's written request made prior
to the making of any alterations and additions,  Landlord shall notify Tenant in
writing as to whether Tenant shall be required to remove any such alterations or
additions, and to so restore the Premises.

(c) All of Tenant's  alterations  and additions and  installation of furnishings
shall be coordinated with any work being performed by Landlord in such manner as
to not damage the Property or interfere with Building  construction or operation
and, except for  installation  of furnishings,  shall be performed by Landlord's
general  contractor or by contractors or workmen first approved by Landlord.  In
the event that Tenant  shall  engage its own  contractors  to perform such work,
Tenant  shall pay to  Landlord  the cost of  services  provided  by  Landlord or
Landlord's  contractor to Tenant and to Tenant's  contractors  while  performing
such work,  which  services  shall  include,  but not be limited  to,  cleaning,
security,  rubbish  removal,  electricity,  toilet  facilities,  and  elevators.
Tenant's  contract with any such  contractors  shall include the Required Tenant
Work General  Conditions  attached  hereto as Exhibit F. and Landlord shall have
the right to enforce such General  Conditions  directly  against any of Tenant's
contractors.  Tenant  shall  defend,  save  harmless,  exonerate  and  indemnify
Landlord from all injury, loss or damage to any person or property occasioned by
or growing out of such work.  Tenant agrees that it will not, either directly or
indirectly,  use any contractors  and/or  materials if their use will create any
difficulty,  whether in the nature of a labor dispute or  otherwise,  with other
contractors  and/or  labor  engaged  by  Tenant  or  Landlord  or  others in the
construction,  maintenance and/or operation of the Building or any part thereof.
Except for work by Landlord's  general  contractor,  Tenant,  before its work is
started,  shall: secure all licenses and permits necessary therefor,  deliver to
Landlord a statement of the names of all its contractors and subconstractors and

                   KBFIII/SOFTWARE DEVELOPER's COMPANY/5.1.96
                    

 the estimated cost of all labor and material to be furnished by them; and cause
 each contractor to carry Workmen's  Compensation Insurance in statutory amounts
 covering  all  the  contractor's  and  subcontractor's  employees,   Automobile
 Liability  Insurance and comprehensive  public liability insurance and property
 damage insurance with such limits as Landlord may reasonably  require but in no
 event less than, with respect to public liability insurance,  $5,000,000.00 and
 with respect to property damage insurance,  $5,000,000.00  (all insurance to be
 written in companies  approved by Landlord and insuring  Landlord and Tenant as
 well as the contractors),  and to deliver to Landlord  certificates of all such
 insurance.  No  installations  or work shall be  undertaken  or begun by Tenant
 until Tenant has made  provision for either  written  waivers of liens from all
 contractors, laborers and suppliers of materials for such installations or work
 the filing of lien bonds on behalf of such contractors, laborers and suppliers,
 or other appropriate  protective measures,  approved by Landlord and Tenant has
 procured  appropriate  surety  payment and  performance  bonds which shall name
 Landlord  as an  additional  obligee  and  Tenant has filed  lien  bond(s)  (in
 jurisdictions  where  available)  on behalf of such  contractors,  laborers and
 suppliers.

 (d) In no event shall any material or equipment be  incorporated in or added to
 the Premises, so as to become a fixture or otherwise a part of the Building, in
 connection  with any such  alteration,  decoration,  installation,  addition or
 improvement which is subject to any lien, charge, mortgage or other encumbrance
 of any kind  whatsoever  or is subject to any security  interest or any form of
 title  retention  agreement.  Any mechanic's lien filed against the Premises or
 the Building  for work  claimed to have been done for, or materials  claimed to
 have been  furnished  to,  Tenant shall be discharged by Tenant within ten (10)
 days  thereafter,  at Tenant's  expense,  by filing the bond required by law or
 otherwise.  If Tenant  fails so to  discharge  any lien,  Landlord may do so at
 Tenant's  expense and Tenant shall  reimburse  Landlord for any expense or cost
 incurred by Landlord in so doing within fifteen (15) days after  rendition of a
 bill therefor.

 (e) All  installations  or work done by Tenant  shall be at its own expense and
 shall at all times  comply  with (i) laws,  rules,  orders and  regulations  of
 governmental  authorities having jurisdiction  thereof;  (ii) orders, rules and
 regulations  of any Board of Fire  Underwriters,  or any other  body  hereafter
 constituted  exercising  similar  functions,  and  governing  insurance  rating
 bureaus;   (iii)  Rules  and  Regulations  of  Landlord;  and  (iv)  plans  and
 specifications  prepared by and at the expense of Tenant theretofore  submitted
 to and approved by Landlord.  All  construction  work  required or permitted by
 this Lease shall be done in a good and workmanlike manner. Tenant agrees to pay
 promptly  when due the entire cost of any work done on the  Premises by Tenant,
 its agents, employees, or independent contractors.

 3.2 REAL ESTATE TAXES ON LEASEHOLD IMPROVEMENTS

 If under  Massachusetts  law or  regulations,  the tax  assessor is required to
 include  leasehold  (real  property)  improvements  in determining the assessed
 value  of the  Building,  then  to  the  extent  that  Tenant  makes  leasehold
 improvements  (including Tenant's original installation and Tenant's subsequent
 alterations,  additions, substitutions and improvements) which are in excess of
 the general standard of improvements in the remainder of the Building,  whether
 done prior to or after the commencement of the Term of this Lease, Tenant shall
 pay the real estate taxes  attributable  to the value of such excess  leasehold
 improvements  throughout  the Term of this Lease within  thirty (30) days after
 being billed therefor by Landlord.

                   KBFIII/SOFTWARE DEVELOPER's COMPANY/5.1.96

3.3 LANDLORD'S RIGHT TO MAKE ALTERATIONS

Landlord reserves the right,  exercisable by itself or its nominee,  at any time
and from time to time without the same  constituting  an actual or  constructive
eviction and without  incurring  any  liability to Tenant  therefor or otherwise
affecting  Tenant's   obligations  under  this  Lease,  to  make  such  changes,
alterations,  additions,  improvements,  repairs  or  replacements  in or to the
Property  (including  the  Building  and the  Premises),  and the  fixtures  and
equipment thereof,  as well as in or to the street entrances,  halls,  passages,
elevators,  escalators,  and  stairways  thereof,  as it may deem  necessary  or
desirable,  and to change  the  arrangement  and/or  location  of  entrances  or
passageways,  doors and doorways, and corridors,  elevators, stairs, toilets, or
other  public  parts  of the  Building  and  other  buildings  on the  Property,
provided,  however,  that there be no  unreasonable  obstruction of the right to
access to, or unreasonable  interference with the use of the Premises by Tenant.
Nothing  contained in this Section 3.3 shall be deemed to relieve  Tenant of any
duty,  obligation  or  liability  of Tenant  with  respect to making any repair,
replacement  or  improvement  or complying with any law, order or requirement of
any governmental or other authority. Landlord reserves the right to adopt at any
time and from time to time to change the name or address of the Building and the
Property.  Neither  this Lease nor any use by Tenant shall give Tenant any right
or easement for the use of any door or any passage or any  concourse  connecting
with any other building or to any public convenience, and the use of such doors,
passes and concourses and of such  conveniences may be regulated or discontinued
at any time and from time to time by  Landlord  without  notice  to  Tenant  and
without  affecting the obligation of Tenant hereunder or incurring any liability
to Tenant therefor, provided, however, that there be no unreasonable obstruction
of the right to  access  to, or  unreasonable  interference  with the use of the
Premises by Tenant.

Landlord shall not be liable to Tenant for any compensation or reduction of rent
by reason of inconvenience or annoyance or for loss of business arising from the
necessity  of  Landlord  or its  agents  entering  the  Premises  for any of the
purposes in this Lease authorized,  or for repairing the Premises or any portion
of the Property or the Building,  however the  necessity  may occur.  Subject to
Section  8.18, in case Landlord is prevented or delayed from making any repairs,
alterations or improvements,  or furnishing any services or performing any other
covenant or duty to be  performed  on  Landlord's  part,  by reason of any cause
reasonably  beyond  Landlord's  control,  Landlord  shall  not  liable to Tenant
therefor, nor except as expressly otherwise provided in Section 6.1 shall Tenant
be entitled to any abatement or reduction of rent by reason  thereof,  nor shall
the same give rise to a claim in Tenant's  favor that such  failure  constitutes
actual or constructive, total or partial, eviction from the Premises.

Landlord  reserves  the  right to stop  any  service  or  utility  system,  when
necessary by reason of accident or emergency,  or until  necessary  repairs have
been completed;  provided,  however,  that in each instance of stoppage Landlord
shall exercise  reasonable  diligence to eliminate the cause thereof.  Except in
case of emergency repairs Landlord will give Tenant reasonable advance notice of
any contemplated  stoppage and will use reasonable  efforts to avoid unnecessary
inconvenience to Tenant by reason thereof.

                   KBFIII/SOFTWARE DEVELOPER's COMPANY/5. 1.96

                                   ARTICLE IV

                 LANDLORD'S COVENANTS; INTERRUPTIONS AND DELAYS

Landlord covenants:

4.1 SERVICES FURNISHED BY LANDLORD

To furnish services, utilities,  facilities and supplies ("LANDLORD'S SERVICES")
set forth in Exhibit D, which Landlord's  Services Landlord shall have the right
to change,  from time to time,  provided that  Landlord's  Services (i.e. at the
time that  Landlord  changes such  services)  shall be equal in quality to those
customarily provided by landlords in comparable buildings in the Waltham area.

4.2 ADDITIONAL SERVICES AVAILABLE TO TENANT

To furnish,  at  Tenant's  expense,  reasonable  additional  Building  operation
services  which are usual and  customary  in  similar  office  buildings  in the
Waltham area upon reasonable  advance request of Tenant at reasonable rates from
time to time established by Landlord.

4.3 ADDITIONAL AIR CONDITIONING EQUIPMENT

In the event Tenant requires  additional air conditioning for business machines,
meeting  rooms or other  special  purposes,  or because of  occupancy  or excess
electrical loads, any additional air conditioning units,  chillers,  condensers,
compressors, ducts, piping and other equipment, such additional air conditioning
equipment will be installed and maintained by Landlord at Tenant's sole cost and
expense, but only if Tenant has obtained Landlord's prior written consent, which
consent shall not be unreasonably withheld and if the same will not cause damage
or injury to the Building or create a dangerous or hazardous condition or entail
excessive or unreasonable  alterations,  repairs or expense or interfere with or
disturb other tenants; and Tenant shall reimburse Landlord in such an amounts as
will  compensate  Landlord for the cost  incurred by Landlord in operating  such
additional air conditioning equipment.

4.4 ROOF, EXTERIOR WALL, FLOOR SLAB, AND COMMON FACILITY REPAIR

Except as  otherwise  provided  in Article VI to make such  repairs to the roof,
exterior walls, floor slabs, and common areas and facilities as may be necessary
to keep them in serviceable condition,  the expense of which shall be charged in
accordance with Section 2.6 or, to the extent any such repairs are required as a
result of the acts or omissions of Tenant, its employees, agents, contractors or
invitees, shall be payable as additional rent by Tenant to Landlord upon demand.

4.5 DOOR SIGNS AND DIRECTORY

To provide and install, at Tenant's expense, letters or numerals on doors in the
Premises to identify  Tenant's name and Building  address;  all such letters and
numerals shall be in the building  standard graphics and no others shall be used
or permitted on the  Premises.  In  addition,  Tenant's  name shall be listed by
Landlord, at Tenant's expense, on the Building directory.

                   KBFIII/SOFTWARE DEVELOPER's COMPANY/5.1.96

4.6 QUIET ENJOYMENT

Landlord  covenants  that if, and so long as, Tenant keeps and performs each and
every covenant, agreement, term, provision and condition herein contained on the
part and on  behalf of Tenant to be kept and  performed,  Tenant  shall  quietly
enjoy the  Premises  from and  against the claims of all  persons  claiming  by,
through or under Landlord subject,  nevertheless, to the covenants,  agreements,
terms,  provisions  and  conditions of this Lease and to any instrument to which
this Lease is subject and subordinate.

                                    ARTICLE V

                               TENANT'S COVENANTS

Tenant  covenants  during the Term and such further time as Tenant  occupies any
part of the Premises:

5.1 PAYMENTS

To pay when due all Annual  Fixed Rent and  additional  rent and all charges for
utility  services  rendered to the  Premises  (except as  otherwise  provided in
Exhibit D) and, as further additional rent, all charges for additional  services
rendered pursuant to Section 4.2;

5.2 REPAIR AND YIELD UP

Except as otherwise provided in Article VI and Section 4.4, to keep the Premises
in good order, repair and condition, reasonable wear and tear only excepted, and
all glass in windows  (except glass in exterior walls of the Building unless the
damage thereto is  attributable  to Tenant's  negligence or misuse) and doors of
the Premises  whole and in good condition with glass of the same quality as that
injured  or  broken  (with  damage  by fire  being  governed  by the  applicable
provisions of this Lease),  and at the  expiration or  termination of this Lease
peaceably to yield up the Premises,  and all alterations and additions  thereto,
in good order,  repair and  condition,  first  removing all goods and effects of
Tenant  and,  to the extent  specified  by  Landlord  by notice to  Tenant,  all
alterations and additions made by Tenant and all  partitions,  and repairing any
damage  caused by such  removal  and  restoring  the  Premises,  and leaving the
Premises clean and neat.

Tenant will remove any personal property from the Building and the Premises upon
or prior to the  expiration or  termination  of this Lease and any such property
which  shall  remain  in  the  Building  or the  Premises  thereafter  shall  be
conclusively  deemed to have been  abandoned,  and may  either  be  retained  by
Landlord  as its  property  or sold or  otherwise  disposed of in such manner as
Landlord  may see fit. If any part  thereof  shall be sold,  then  Landlord  may
receive and retain the proceeds of such sale and apply the same,  at its option,
against the expenses of the sale, the cost of moving and storage, any arrears of
Annual Fixed Rent,  additional or other charges  payable  hereunder by Tenant to
Landlord  and any damages to which  Landlord may be entitled  under  Section 7.2
hereof or pursuant to law.

5.3 USE

Continuously  from the  commencement  of the Term to use and occupy the Premises
for the Permitted  Uses,  and not to injure or deface the Premises,  Building or
Property,  nor to permit in the Premises any auction sale,  vending machine,  or
inflammable fluids or chemicals,  or nuisance, or the emission from the Premises
of any  objectionable  noise or odor,  nor to use or devote the  Premises or any
part thereof for any purpose other than the

                   KBFIII/SOFTWARE DEVELOPER's COMPANY/5.1.96

Permitted Uses, nor any use thereof which is  inconsistent  with the maintenance
of the Building as an office building of first class quality in maintenance, use
and occupancy, or which is improper,  offensive, contrary to law or ordinance or
liable to invalidate or increase the premiums for any insurance on the Building,
its contents or the Property,  or liable to render  necessary any  alteration or
addition to the Building of the Property.

5.4 OBSTRUCTIONS, ITEMS VISIBLE FROM EXTERIOR; RULES AND REGULATIONS

Not to obstruct in any manner any portion of the Building  not hereby  leased or
any portion thereof or of the Property used by Tenant in common with others; not
without  prior  consent of  Landlord  to permit the  painting  or placing of any
signs, curtains,  blinds, shades,  awnings,  aerials or flagpoles,  or the like,
visible from outside the Premises;  and to comply with all reasonable  Rules and
Regulations  now or hereafter  made by Landlord,  or which Tenant has been given
notice,  for the care and use of the Building and Property and their  facilities
and approaches;  Landlord shall not be liable to Tenant for the failure of other
occupants of the Property to conform to such Rules and Regulations.

5.5 SAFETY APPLIANCES

To keep the  Premises  equipped  with all safety  appliances  required by law or
ordinance or any other  regulation  of any public  authority  because of any use
made by Tenant  other than normal  office use,  and to procure all  licenses and
permits so required because of such use and, if requested by Landlord, to do any
work so required  because of such use, it being  understood  that the  foregoing
provisions shall be construed to broaden in any way Tenant's Permitted Uses.

5.6 ASSIGNMENT; SUBLEASE

Tenant  covenants  and agrees  that  neither  this Lease nor the term and estate
hereby granted, nor any interest herein or therein, will be assigned, mortgaged,
pledged,  encumbered or otherwise transferred,  voluntarily, by operation of law
or  otherwise,  and that  neither the  Premises,  nor any part  thereof  will be
encumbered in any manner by reason of any act or omission on the part of Tenant,
or used or occupied,  or permitted to be used or occupied,  or utilized for desk
space or mailing  privileges,  by anyone  other than  Tenant,  or for any use or
purposes  other than the  Permitted  Uses stated in Article 1, or be sublet,  or
offered or advertised for any of the foregoing.  Notwithstanding  the foregoing,
it  is  hereby  expressly  understood  and  agreed,  however,  if  Tenant  is  a
corporation,  that the  assignment  or transfer of this Lease,  and the term and
estate hereby granted,  to any  corporation  into which Tenant is merged or with
which Tenant is consolidated  which  corporation shall have a net worth at least
equal to that of Tenant immediately prior to such merger or consolidation  (such
corporation  being  hereinafter  called  "ASSIGNEE"),  shall not be deemed to be
prohibited hereby if, and upon the express  condition that,  Assignee and Tenant
shall promptly execute, acknowledge and deliver to Landlord an agreement in form
and  substance  satisfactory  to  Landlord  whereby  Assignee  shall agree to be
independently bound by and upon all the covenants, agreements, terms, provisions
and  conditions  set forth in this Lease on the part of Tenant to be  performed,
and whereby  Assignee shall  expressly agree that the provisions of this Section
5.6 shall,  notwithstanding such assignment or transfer,  continue to be binding
upon Assignee with respect to all future assignments and transfers.

Notwithstanding   the  foregoing  to  the  contrary,   Landlord  agrees  not  to
unreasonably  withhold  its  consent  to a  sublease  of all or a portion of the
Premises  provided  that (i) the Premises  shall not be  subdivided  at any time
during the Term);  (ii)  Tenant  shall not  sublease  or  advertise  or offer to
sublease  any part of the  Premises  for a rent  which is less  than the rent at
which space in the Property is then being offered by Landlord; (iii) Tenant

                   KBFIII/SOFTWARE DEVELOPER's COMPANY/5.1.96

shall not sublease or advertise or offer to sublease any part of the Premises to
any entity with which Landlord is then  currently  negotiating or has within six
months prior  thereto  negotiated  for space in the  Property,  or to any entity
which is a tenant of the  Property;  (iv) the  proposed  subtenant  shall have a
business  reputation  and use  which is  appropriate  for a first  class  office
building; (v) the proposed subtenant has the financial ability to fulfill all of
its obligations under the proposed sublease;  (vi) Tenant pays to Landlord fifty
percent  (50%) of the  amount by which the rent,  additional  charges  and other
compensation  received by Tenant from the  subtenant  exceeds the sum of (A) the
rent and additional charges payable by Tenant under the Lease for the comparable
portion of the Term minus (B) the reasonable out of pocket expenses  incurred by
Tenant with respect to the sublease as amortized  over the term of the sublease;
and (vii) the  proposed  subtenant  agrees in  writing,  in form  acceptable  to
Landlord in the  exercise of  reasonable  business  judgment,  that its sublease
shall be subject to all of the terms and conditions of this Lease.

If Tenant is an individual who uses and/or  occupies the Premises with partners,
or if Tenant is a partnership, then:

(i) Each present and future partner shall be personally bound by and upon all of
the covenants,  agreements,  terms,  provisions and conditions set forth in this
Lease on the part of Tenant to be performed; and

(ii) In confirmation of the foregoing,  Landlord may (but without being required
to do so) request (and Tenant  shall duly comply) that Tenant,  at the time that
Tenant  admits any new partner to its  partnership,  shall require each such new
partner to execute an agreement in form and substance  satisfactory  to Landlord
whereby such new partner shall agree to be  personally  bound by and upon all of
the covenants, agreements, terms, provisions and conditions of this Lease on the
part of Tenant to be performed, without regard to the time when such new partner
is admitted to partnership  or when any  obligations  under any such  covenants,
etc., accrue.

The  listing of any name other than that of Tenant,  whether on the doors of the
Premises or on the Building directory,  or otherwise,  shall not operate to vest
in any such other  person,  firm or  corporation  any right or  interest in this
Lease or in the  premises  or be deemed to effect or  evidence  any  consent  of
Landlord,  it being  expressly  understood  that any such listing is a privilege
extended by Landlord revocable at will by written notice to Tenant.

If this Lease be  assigned,  or if the Premises or any part thereof be sublet or
occupied by anybody  other than Tenant,  Landlord may, at any time and from time
to time,  collect  rent  and  other  charges  from the  assignee,  subtenant  or
occupant,  and  apply the net  amount  collected  to the rent and other  charges
herein  reserved,  then  due and  hereafter  becoming  due,  but no  assignment,
subletting,  occupancy or collection  shall be deemed a waiver of this covenant,
or the  acceptance  of the  assignee,  subtenant  or occupant as a tenant,  or a
release of Tenant from the further  performance  by Tenant of  covenants  on the
part of Tenant  herein  contained.  Any  consent  by  Landlord  to a  particular
assignment or subletting shall not in any way diminish the prohibition stated in
the first sentence of this Section 5.6 or the continuing liability of the Tenant
named in Article 1 as the party-Tenant under this Lease.

No  assignment  or  subletting  or use of the Premises by an affiliate of Tenant
shall affect the Permitted  Uses for which the Premises may be used as stated in
Article 1.

                   KBFIII/SOFTWARE DEVELOPER's COMPANY/5.1.96

5.7 INDEMNITY, INSURANCE

To defend with counsel first approved by Landlord,  save harmless, and indemnify
Landlord from any liability for injury,  loss,  accident or damage to any person
or property, and from any claims, actions, proceedings and expenses and costs in
connection therewith (including without limitation reasonable counsel fees), (i)
arising  from  (a)  the  omission,  fault,  willful  act,  negligence  or  other
misconduct of Tenant, or of Tenant's  employees,  agents or contractors,  or (b)
from any use made or thing  done or  occurring  on the  Premises  not due to the
omission,  fault,  willful act, negligence or other misconduct of Landlord or of
Landlord's employees, agents, or contractors, or (ii) resulting from the failure
of Tenant to perform and  discharge its  covenants  and  obligations  under this
Lease;  to maintain in responsible  companies  qualified to do business,  and in
good standing, in Massachusetts public liability insurance covering the Premises
insuring Landlord as well as Tenant with limits which shall, at the commencement
of the Term,  be at least  equal to those  stated in  Article 1 and from time to
time during the Term shall be for such higher limits,  if any as are customarily
carried in the Waltham area with respect to similar  properties,  and  Workmen's
Compensation  Insurance with statutory limits covering all of Tenant's employees
working in the Premises,  and to deposit promptly with Landlord certificates for
such  insurance,  and all  renewals  thereof  bearing the  endorsement  that the
policies  will not be  canceled  until  after ten (10) days'  written  notice to
Landlord.

5.8 PERSONAL PROPERTY AT TENANT'S RISK

That all of the furnishings,  fixtures, equipment, effects and property of every
kind, nature and description of Tenant,  and all persons claiming by, through or
under Tenant which, during the continuance of this Lease or any occupancy of the
Premises by Tenant or anyone  claiming  under Tenant,  may be on the Premises or
elsewhere in the Building or on the Lot, shall be at the sole risk and hazard of
Tenant,  and if the whole or any part  thereof  shall be destroyed or damaged by
fire,  water or otherwise,  or by the leakage or bursting of water pipes,  steam
pipes, or other pipes, by theft or from any other cause, no part of said loss or
damage is to be charged to or be borne by Landlord.

5.9 RIGHT OF ENTRY

To permit Landlord and its agents:  to examine the Premises at reasonable  times
and, if Landlord shall so elect,  to make any repairs or  replacements  Landlord
may deem necessary; to remove, at Tenant's expense, any alterations,  additions,
signs, curtains,  blinds, shades, awnings,  aerials,  flagpoles, or the like not
consented to in writing;  and to show the Premises to prospective Tenants during
the  eighteen  months  preceding  expiration  of the  Term  and  to  prospective
purchasers and mortgagees at all reasonable times.

Without  incurring  any  liability to Tenant,  Landlord may permit access to the
Premises  and open the same,  whether or not Tenant  shall be present,  upon any
demand or any receiver, trustee, assignee for the benefit of creditors, sheriff,
marshal or court officer  entitled to, or  reasonably  purporting to be entitled
to, such access for the purposes of taking possession of, or removing,  Tenant's
property or for any other lawful  purposes (but this provision and any action by
Landlord hereunder shall not be deemed a recognition by Landlord that the person
or official making such demand has any right or interest in or to this Lease, or
in or to the  premises),  or upon  demand  of any  representation  of the  fire,
police,  building,  sanitation or other department of the city, state or federal
governments.

                   KBFIII/SOFTWARE DEVELOPER's COMPANY/5.1.96

5.10 FLOOR LOAD; PREVENTION OF VIBRATION AND NOISE

Not to place a load upon the Premises  exceeding an average rate of 90 pounds of
live load per square foot of floor area (partitions  shall be considered as part
of the live  load);  Landlord  reserves  the right to  prescribe  the weight and
position of all safes,  files and heavy  equipment which Tenant desires to place
in the  Premises so as  properly  to  distribute  the weight  thereof;  Tenant's
business  machines and mechanical  equipment which cause vibration or noise that
may be  transmitted  to the  Building  structure  or to any  other  space in the
Building  shall be so installed,  maintained  and used by Tenant as to eliminate
such vibration or noise.

5.11 PERSONAL PROPERTY TAXES

To pay promptly when due all taxes which may be imposed upon  personal  property
(including  without  limitation,  fixtures  and  equipment)  in the  Premises to
whomever assessed.

5.12 PAYMENT OF LITIGATION EXPENSES

As additional rent, to pay all reasonable costs, counsel and other fees incurred
by Landlord in connection with the enforcement by Landlord of any obligations of
Tenant under this Lease.

5.13 COMPLIANCE WITH INSURANCE REGULATIONS

Not to do or permit to be done any act or thing  upon the  Premises  which  will
invalidate or be in conflict with the terms of the  Massachusetts  standard form
of fire,  boiler,  sprinkler,  water damage or other insurance policies covering
the Building and the fixtures and property  therein;  Tenant  shall,  at its own
expense,  comply with all rules,  regulations,  and requirements of the National
Board  of  Fire   Underwriters  or  any  state  or  other  similar  body  having
jurisdiction,  and shall not  knowingly  do or permit  anything to be done in or
upon the Premises in a manner which  increases the rate of fire  insurance  upon
the Building, the Property or on any property or equipment located therein.

5.14 SUBJECT TO APPLICABLE LAW

Notwithstanding  any provision of this Lease to the contrary,  Landlord shall in
no event be  indemnified  or held harmless or  exonerated  from any liability to
Tenant or to any person, for any injury, loss, damage or liability to the extend
such  indemnity,  hold harmless or  exoneration  is prohibited by law,  provided
Tenant agrees that,  prior to making any claims  against  Landlord  (and, to the
extent Tenant is successful,  in place of any such claims),  Tenant shall pursue
all other available remedies  including,  without  limitation,  seeking recovery
under Tenant's insurance policies.

5.15 REQUIREMENTS OF LAW - FINES AND PENALTIES

Tenant,  at its sole  expense,  shall  comply with all laws,  rules,  orders and
regulations,  including, without limitation, all energy-related requirements, of
Federal,  State, County and Municipal  Authorities and with any direction of any
public  officer or officers,  pursuant to law,  which shall impose any duty upon
Landlord or Tenant with  respect to or arising out of Tenant's  use or occupancy
of the  Premises.  Tenant  shall  reimburse  and  compensate  Landlord  for  all
expenditures made by, or damages or fines sustained or incurred by, Landlord due
to  nonperformance  or  noncompliance  with or breach or failure to observe  any
item,  covenant,  or  condition  of this  Lease upon  Tenant's  part to be kept,
observed,

                   KBFIII/SOFTWARE DEVELOPER's COMPANY/5.1.96

performed or complied with. If Tenant  receives  notice of any violation of law,
ordinance,  order or regulation applicable to the Premises, it shall give prompt
notice thereof to Landlord.

                                   ARTICLE VI

                               CASUALTY AND TAKING

6.1 Termination or Restoration; Rent Adjustment

In case during the Term all or any part of the  Premises or the  Building or the
Property are damaged materially by fire or other casualty or by action of public
or other  authority in  consequence  thereof,  or are taken by eminent domain or
Landlord  receives  compensable  damage by reason of anything  lawfully  done in
pursuance of public or other authority, this Lease shall terminate at Landlord's
election, which may be made notwithstanding  Landlord's entire interest may have
been  divested,  by  notice  given to Tenant  within  six (6)  months  after the
casualty or taking  specifying the effective date of termination.  The effective
date of  termination  specified  by Landlord  shall not be less than 15 nor more
than 30 days  after the date of notice of such  termination.  Unless  terminated
pursuant to the foregoing provisions,  this Lease shall remain in full force and
effect following any such damage or taking,  subject,  however, to the following
provisions.  If in any such case the  Premises  are  rendered  unfit for use and
occupation and this Lease is not so terminated, Landlord shall use due diligence
(following  the  expiration of the period in which  Landlord may terminate  this
Lease pursuant to the foregoing  provisions of this Section 6.1), subject to the
then applicable statutes,  building codes, zoning ordinances, and regulations of
any  governmental  authority  and at the  expense of  Landlord  (but only to the
extent of insurance proceeds made available to Landlord) to put the Premises, or
in case of taking what may remain  thereof  (excluding  in case of both casualty
and  taking  any items  installed  or paid for by  Tenant  which  Tenant  may be
required to remove pursuant to Section 5.2),  into proper  condition for use and
occupation and a just  proportion of the Annual Fixed Rent and  additional  rent
according  to the nature and extent of the injury  shall be abated from the date
of such casualty or taking until the Premises or such remainder  shall have been
put by  Landlord  in such  condition;  and in case of taking  which  permanently
reduces the area of the Premises, a just proportion of the Annual Fixed Rent and
additional rent shall be abated for the remainder of the Term.

6.2 EMINENT DOMAIN

Landlord  reserves  to itself  any and all  rights to  receive  awards  made for
damages  to the  Premises,  Building  and  Property,  and the  leasehold  hereby
created,  or any one or more of them,  accruing by reason of exercise of eminent
domain or by reason of anything  lawfully  done in  pursuance of public or other
authority. Tenant hereby releases and assigns to Landlord all Tenant's rights to
such awards,  and covenants to deliver such further  assignments  and assurances
thereof  as  Landlord  may  from  to time  request.  Tenant  hereby  irrevocably
designates and appoints Landlord as its  attorney-in-fact to execute and deliver
in   Tenant's   name  and  behalf   all  such   further   assignments   thereof.
Notwithstanding  the foregoing to the  contrary,  Tenant shall have the right to
retain any separate  award for the Tenant's  relocation  expenses which does not
reduce Landlord's award.

6.3 TEMPORARY TAKING

In the event of a taking of the Premises or any part thereof for  temporary  use
(less than 365 days), (i) this Lease shall be and remain unaffected  thereby and
rent shall not abate, and (ii)

                   KBFIII/SOFTWARE DEVELOPER's COMPANY/5.1.96

Tenant  shall be entitled to receive for itself such  portion or portions of any
award made for such use with respect to the period of the taking which is within
the Term,  provided that if such taking shall remain in force at the  expiration
or earlier  termination  of this Lease,  Tenant shall then pay to Landlord a sum
equal to the reasonable cost of performing  Tenant's  obligations  under Section
5.2 with respect to  surrender  of the  Premises and upon such payment  shall be
excused from such obligations.

                                   ARTICLE VII

                                     DEFAULT

7.1 EVENTS OF DEFAULT

If (a) Tenant  shall  neglect or fail to  perform  or  observe  any of  Tenant's
covenants or  agreements  herein,  including  the  obligation  to pay, when due,
Annual Fixed Rent or additional rent, and such failure continues, in the case of
Annual Fixed Rent or additional  rent, for more than ten (10) days after written
notice of such  default,  or in any other  case,  for more than thirty (30) days
after  written  notice of such default and such  additional  time, if any, as is
reasonably necessary to cure the default if the default is of such a nature that
it cannot  reasonably be cured in thirty (30) days,  provided  however,  that no
such  notice  need be given and no such  default  shall be curable if on two (2)
prior occasions within the same calendar year there had been a default which had
been cured after  notice  thereof had been given by Landlord to Tenant as herein
provided (i.e.  Landlord shall have the right in any such event to terminate the
Lease  immediately upon the occurrence of such default without giving Tenant any
opportunity to cure such default) or if Tenant or any guarantor or any guarantor
of any of Tenant's  obligations under this Lease, (b) is not paying its debts as
such debts become due, becomes insolvent,  seeks relief under any chapter of the
U.S. Bankruptcy Code (or any insolvency or similar law of any jurisdiction),  or
(c) proposes any dissolution, liquidation, composition, financial reorganization
or recapitalization with creditors; or (d) makes an assignment or trust mortgage
for the benefit of creditors or (e) if a receiver, trustee, custodian or similar
agent is appointed or takes  possession with respect to any property or business
of Tenant or such guarantor,  or (f) Tenant shall desert or abandon the Premises
or the same shall become,  or appear to have become,  vacant (whether or not the
key shall have been  surrendered  or the rent shall have been paid),  or (g) any
event shall occur or any contingency shall arise whereby this Lease, or the term
and estate  thereby  created,  would (by operation of law or otherwise)  desolve
upon or pass to any person,  firm or  corporation  other than Tenant,  except as
expressly  permitted under Section 5.6 hereof then, in any such case, whether or
not the Term shall have begun,  Landlord may  immediately,  or at any time while
such default exists and without further notice, terminate this Lease by entry by
Landlord or upon the giving of notice to Tenant, and this Lease shall come to an
end as fully and  completely  as if such date  were the date  herein  originally
fixed for the  expiration of the Term,  and Tenant shall then quit and surrender
the  Premises  to  Landlord,  but  Tenant  shall  remain  liable as  hereinafter
provided.

7.2 DAMAGES

In the event that this Lease is terminated under any of the provisions contained
in Section 7.1 or shall be otherwise  terminated for breach of any obligation of
Tenant,  Tenant  covenants to pay forthwith to Landlord,  as  compensation,  the
excess of the total rent  reserved  for the  residue of the Term over the rental
value of the  Premises  for said residue of the Term.  In  calculating  the rent
reserved  there shall be included,  in addition to the Annual Fixed Rent and all
additional  rent,  the  value of all other  considerations  agreed to be paid or
performed by Tenant for said residue.  Tenant further covenants as an additional
and

                   KBFIII/SOFTWARE DEVELOPER's COMPANY/5.1.96

cumulative  obligation  after any such ending to pay  punctually to Landlord all
the sums and perform all the obligations which Tenant covenants in this Lease to
pay and to  perform in the same  manner  and to the same  extent and at the same
time as if this Lease had not been terminated.  In calculating the amounts to be
paid by Tenant under the next foregoing  covenant  Tenant shall be credited with
any amount paid to Landlord as  compensation as in this Section 7.2 provided and
also with the net  proceeds of any rent  obtained by Landlord by  reletting  the
Premises,  after  deducting  all  Landlord's  expenses in  connection  with such
reletting,  including,  without limitation,  all repossession  costs,  brokerage
commissions,  fees for legal services and expenses of preparing the Premises for
such  reletting,  it being  agreed by  Tenant  that  Landlord  may (i) relet the
Premises  or any  part or  parts  thereof,  for a term  or  terms  which  may at
Landlord's  option be equal to or less than or exceed  the  period  which  would
otherwise  have  constituted  the  balance  of  the  Term  and  may  grant  such
concessions and free rent as Landlord in its sole judgment  considers  advisable
or  necessary  to relet  the same and (ii) make such  alterations,  repairs  and
decorations in the Premises as Landlord in its sole judgment considers advisable
or necessary to relet the same, and no action of Landlord in accordance with the
foregoing or failure to relet or to collect rent under  reletting  shall operate
or be construed to release or reduce Tenant's liability as aforesaid.

In lieu of any  other  damages  or  indemnity  and in lieu of full  recovery  by
Landlord of all sums payable under all the foregoing  provisions of this Section
7.2,  Landlord may by written notice to Tenant,  at any time after this Lease is
terminated under any of the provisions  contained in Section 7.1 or is otherwise
terminated for breach of any obligation of Tenant and before such full recovery,
elect to recover,  and Tenant shall  thereupon  pay, as liquidated  damages,  an
amount  equal to the  aggregate  of the Annual  Fixed Rent and  additional  rent
accrued  under  Section 2.5,  2.6 and 2.7 in the 12 months ended next  following
such termination plus the amount of Annual Fixed Rent and additional rent of any
kind  accrued and unpaid at the time of  termination  and less the amount of any
recovery by Landlord  under the  foregoing  provisions of this Section 7.2 up to
the time of payment of such liquidated damages.

Nothing  contained in this Lease shall limit or prejudice  the right of Landlord
to prove for and obtain in proceedings for bankruptcy or insolvency by reason of
the  termination  of this Lease,  an amount equal to the maximum  allowed by any
statute or rule of law in effect at the time when, and governing the proceedings
in which,  the damages  are to be proved,  whether or not the amount be greater,
equal to, or less than the amount of the loss or damages referred to above.

                                  ARTICLE VIII

                                  MISCELLANEOUS

8.1 COMPUTATION OF RENTABLE FLOOR AREAS

For all  purposes of this Lease,  the  rentable  floor area is the gross area of
Tenant's  Space  measured  from the plane of the inside  surface of the exterior
glass line to the middle of the demising  walls,  and adding a pro-rata share of
all Building common areas, but allowing no deductions for columns or projections
within such Tenant's Space. For purposes hereof, the Building common areas shall
include  (a) any public  elevator  shafts,  elevator  machine  rooms,  machinery
shafts,  and  common  stairways  and  stairwells,  (b) on  multi-tenant  floors,
restrooms,  elevator lobby,  janitor closets,  common corridors,  and mechanical
rooms, and (c) the first and third floor lobbies,  and electrical  equipment and
mechanical rooms.

                   KBFIII/SOFTWARE DEVELOPER's COMPANY/5.1.96

8.2 NOTICE OF LEASE; CONSENT OF APPROVAL; NOTICES; BIND AND INURE

(a) The  titles  of the  Articles  are for  convenience  only  and are not to be
considered in construing this Lease.

(b) Tenant  agrees not to record this Lease,  but upon  request of either  party
both  parties  shall  execute  and  deliver  a  notice  of  this  Lease  in form
appropriate  for  recording  or  registration,  and if this Lease is  terminated
before the term expires,  an instrument in such form  acknowledging  the date of
termination.

(c) Whenever any notice, approval, consent, request or election is given or made
pursuant to this Lease it shall be in writing. Communications and payments shall
be  addressed  if to Landlord at  Landlord's  Original  Address or at such other
address as may have been specified by prior notice to Tenant,  and if to Tenant,
at Tenant's  Original  Address or at such other place as may have been specified
by prior notice to Landlord. Any communication so addressed shall be deemed duly
given when mailed by registered or certified mail, return receipt requested.  If
Landlord by notice to Tenant at any time designates some other person to receive
payments or notices,  all payments or notices thereafter by Tenant shall be paid
or given to the person  designated  until  notice to the contrary is received by
Tenant from Landlord.

(d) The  obligations of this Lease shall run with the land, and this Lease shall
be  binding  upon and  inure to the  benefit  of the  parties  hereto  and their
respective successors and assigns,  except that only the original Landlord named
herein  shall be liable for  obligations  accruing  before the  beginning of the
Term,  and thereafter  the original  Landlord  named herein and each  successive
owner of the Premises shall be liable only for  obligations  accruing during the
period of ownership.

8.3 LANDLORD'S FAILURE TO ENFORCE

The  failure of Landlord to seek  redress  for  violation  of, or to insist upon
strict  performance of, any covenant or condition of this Lease, or with respect
to such failure of Landlord to enforce any of the Rules and Regulations referred
to in Section 5.4, whether  heretofore or hereafter  adopted by Landlord,  shall
not be deemed a waiver of such  violation  nor  prevent a  subsequent  act which
would have  originally  constituted  a violation,  from having all the force and
effect of an  original  violation,  nor shall the failure of Landlord to enforce
any of said Rules and  Regulations  against any other  tenant of the Property be
deemed a waiver of any such Rule or  Regulation.  The  receipt  by  Landlord  of
Annual  Fixed  Rent or  additional  rent  with  knowledge  of the  breach of any
covenant of this Lease shall not be deemed a waiver of such breach. No provision
of this Lease  shall be deemed to have been  waived by  Landlord,  or by Tenant,
unless such waiver be in writing  signed by the party to be charged.  No consent
or waiver, express or implied, by Landlord or Tenant, to or of any breach of any
agreement  or duty shall be  construed as a waiver or consent to or of any other
breach of the same or any other agreement or duty.

8.4 ACCEPTANCE OF PARTIAL PAYMENTS OF RENT; DELIVERY OF KEYS

No  acceptance  by  Landlord  of a lesser  sum than the  Annual  Fixed  Rent and
additional  rent then due shall be deemed  to be other  than on  account  of the
earliest installment of such rent due, nor shall any endorsement or statement on
any check or any letter  accompanying  any check or payment as rent be deemed an
accord and  satisfaction,  and Landlord may accept such check or payment without
prejudice  to  Landlords  right to recover  the balance of such  installment  or
pursue any other remedy in this Lease provided. The delivery of keys to any

                   KBFIII/SOFTWARE DEVELOPER's COMPANY/5.1.96

employee of Landlord or to  Landlord's  agent or any employee  thereof shall not
operate as a termination of this Lease or surrender of the Premises.

8.5 CUMULATIVE REMEDIES

The specific remedies to which Landlord may resort under the terms of this Lease
are  cumulative  and are not intended to be  exclusive of any other  remedies or
means of redress to which it may be  lawfully  entitled in case of any breach or
threatened  breach by Tenant of any  provisions  of this  Lease.  In addition to
other  remedies  provided  in this  Lease,  Landlord  shall be  entitled  to the
restraint by injunction of the violation or attempted or threatened violation of
any of the  covenants,  conditions  or  provisions  of this Lease or to a decree
compelling specific performance of any such covenants, conditions or provisions.

8.6 PARTIAL INVALIDITY

If any  term  of  this  Lease,  or the  application  thereof  to any  person  or
circumstances, shall to any extent be invalid or unenforceable, the remainder of
this Lease,  or the application of such term to persons or  circumstances  other
than  those as to which it is  invalid or  unenforceable  shall not be  affected
thereby,  and each  term of this  Lease  shall be valid and  enforceable  to the
fullest extent permitted by law.

8.7 SELF-HELP

If Tenant shall at any time fail to promptly  perform any obligation  under this
Lease, Landlord shall have the right, but shall not be obligated,  to enter upon
the  Premises and to perform such  obligation  notwithstanding  the fact that no
specific provision for such substituted  performance by Landlord is made in this
Lease with respect to such default. In performing such obligation,  Landlord may
make any payment of money or perform any other act. All sums so paid by Landlord
(together  with  interest at the rate of 2 1/2  percentage  points over the then
prevailing prime rate as set forth in The Wall Street Journal) and all necessary
incidental costs and expenses in connection with the performance of any such act
by Landlord, shall be deemed to be additional rent under this Lease and shall be
payable to Landlord  immediately on demand.  Landlord may exercise the foregoing
rights without  waiving any other of its rights or releasing  Tenant from any of
its obligations under this Lease.

8.8 TENANT'S ESTOPPEL CERTIFICATE

Tenant  agrees from time to time,  upon not less than  fifteen  (15) days' prior
written request by Landlord,  to execute,  acknowledge and deliver to Landlord a
statement in writing  certifying that this Lease is unmodified and in full force
and effect and that Tenant has no defenses, offsets or counterclaims against its
obligations to pay the Annual Fixed Rent and additional  rent and to perform its
other  covenants  under this Lease and that  there are no  uncured  defaults  of
Landlord or Tenant  under this lease (or,  if there have been any  modifications
that  the  same  is in full  force  and  effect  as  modified  and  stating  the
modifications  and,  if  there  are any  defenses,  offsets,  counterclaims,  or
defaults,  setting them forth in reasonable detail),  and the dates to which the
Annual Fixed Rent,  additional  rent and other charges have been paid.  Any such
statement  delivered  pursuant  to  this  Section  8.8 may be  relied  upon by a
prospective  purchaser or mortgagee of the Premises or any prospective  assignee
of any mortgagee of the Premises.  Time is of the essence in respect of any such
requested  certificate,  Tenant  hereby  acknowledging  the  importance  of such
certificates in mortgage financing arrangements,  prospective sale and the like.
Tenant hereby appoints Landlord Tenant's attorney-in-fact in its name and behalf
to execute such statement if Tenant shall fail to execute such statement  within
such fifteen-(15)-day period.

                   KBFIII/SOFTWARE DEVELOPER's COMPANY/5.1.96

8.9 WAIVER OF SUBROGATION

In any case in which  Tenant  shall be  obligated  to pay to Landlord  any loss,
cost, damage,  liability, or expense suffered or incurred by Landlord,  Landlord
shall  allow to Tenant as an  offset  against  the  amount  thereof  (i) the net
proceeds of any insurance  collected by Landlord for or on account of such loss,
cost, damage,  liability or expense,  provided that the allowance of such offset
does not  invalidate  or  prejudice  the  policy or  policies  under  which such
proceeds were payable, and (ii) if such loss, cost, damage, liability or expense
shall have been caused by a peril against  which  Landlord has agreed to procure
insurance  coverage under the terms of this Lease,  the amount of such insurance
coverage, whether or not actually procured by Landlord.

In any case in which Landlord or Landlord's  agents shall be obligated to pay to
Tenant any loss,  cost,  damage,  liability  or expense  suffered or incurred by
Tenant,  Tenant  shall  allow to  Landlord  and  Landlord's  agents as an offset
against the amount  thereof (i) the net proceeds of any  insurance  collected by
Tenant for or on account of such loss,  cost,  damage,  liability,  or  expense,
provided  that the  allowance of such offset does not  invalidate  the policy or
policies under which such proceeds were payable and (ii) the amount of any loss,
cost, darnage,  liability or expense caused by a peril covered by fire insurance
with the broadest form of property insurance  generally available on property in
buildings  of the type of the  Building,  whether or not  actually  procured  by
Tenant.

The parties hereto shall each procure an  appropriate  clause in, or endorsement
on, any  property  insurance  policy  covering the premises and the Building and
personal property,  fixtures and equipment located thereon and therein, pursuant
to which the insurance  companies  waive  subrogation  or consent to a waiver of
right of recovery.  Having obtained such clauses and/or  endorsements each party
hereby  agrees that it will not make any claim  against or seek to recover  from
the  other  for any loss or damage to its  property  or the  property  of others
resulting from firm or other perils covered by such property insurance.

8.10 ALL AGREEMENTS CONTAINED

This Lease  contains  all of the  agreements  of the parties with respect to the
subject  matter  thereof and  supersedes  all prior  dealings  between them with
respect to such subject matter.

8.11 BROKERAGE

Landlord and Tenant each warrant that they have had no dealings  with any broker
or agent  other  than LYNCH  MURPHY  WALSH & PARTNERS  and RADER  PROPERTIES  in
connection  with the Lease and covenant to defend,  hold  harmless and indemnify
each other from and  against  any and all cost,  expense  or  liability  for any
compensation, commissions and charges claimed by any broker or agent claiming by
or through  them with respect to dealings in  connection  with this Lease or the
negotiation thereof

8.12 SUBMISSION NOT AN OPTION

The  submission of this Lease or a summary of some or all of its  provisions for
examination  does not  constitute a reservation of or option for the Premises or
an offer to lease.

8.13 APPLICABLE LAW

This  Lease,  and the rights and  obligations  of the parties  hereto,  shall be
construed  and  enforced  in  accordance  with the laws of the  Commonwealth  of
Massachusetts.

                   KBFIII/SOFTWARE DEVELOPER's COMPANY/5.1.96

8.14 WAIVER OF JURY TRIAL

Landlord  and Tenant  hereby  waive trial by jury in any action,  proceeding  or
counterclaim brought by either of the parties hereto against the other, on or in
respect to any matter  whatsoever  arising out of or in any way  connected  with
this Lease, the relationship of Landlord and Tenant  hereunder,  Tenant's use or
occupancy of the Premises, and/or claim of injury or damages.

8.15 HOLDOVER

If Tenant or anyone  claiming  under Tenant shall  remain in  possession  of the
Premises or any part thereof after the  expiration or prior  termination  of the
term of this Lease without any agreement in writing between  Landlord and Tenant
with respect thereto,  then, prior to the acceptance of any payments for rent or
use and  occupancy by Landlord,  the person  remaining  in  possession  shall be
deemed a  tenant-at-sufferance.  Whereas the  parties  hereby  acknowledge  that
Landlord may need the Premises after the expiration or prior  termination of the
term of the Lease for other  tenants and that the  damages  which  Landlord  may
suffer as the result of Tenant's  holding-over  cannot be  determined  as of the
date of this Lease, in the event that Tenant so holds over,  Tenant shall pay to
Landlord in addition to all rental and other  charges due and accrued  under the
Lease  prior to the date of  termination,  charges  (based  upon the fair market
rental value of the Premises) for use and occupation of the Premises  thereafter
and, in addition to such sums and any and all other  rights and  remedies  which
Landlord may have at law or in equity, an additional use and occupancy charge in
the amount of fifty  percent  (50%) of either  the  Annual  Fixed Rent and other
charges  calculated  (on a daily basis) at the highest  rate  payable  under the
terms of this  Lease,  but  measured  from the day on which  Tenant's  hold-over
commenced and terminating on the day on which Tenant vacates the Premises or the
fair market rental value of the Premises for such period,  whichever is greater.
Notwithstanding the foregoing, Landlord shall have the right to elect to recover
any other  damages  which  Landlord is permitted to recover  under this Lease in
lieu  of said  liquidated  damages  by  giving  Tenant  written  notice  of such
election.  From and after the date on which  Landlord  gives Tenant such notice,
said  liquidated  damages  shall  cease to accrue and Tenant  shall be liable to
Landlord for any damages recoverable under this Lease which accrue thereafter.

8.16 ARBITRATION

Any disputes  relating to provisions or  obligations in this Lease as to which a
specific  provision  for a reference  to  arbitration  is made  herein  shall be
submitted to arbitration in accordance  with the provisions of applicable  state
law, as from time to time  amended,  provided that in no event shall Tenant have
the right to require  arbitration of any matter relating to Tenant's  obligation
to pay Annual  Fixed Rent,  additional  rent or any other  charges.  Arbitration
proceedings,  including  the  selection  of an  arbitrator,  shall be  conducted
pursuant to the rules, regulations and procedures from time to time in effect as
promulgated  by the American  Arbitration  Association.  Prior written notice of
application by either party for arbitration shall be given to the other at least
ten (10) days before  submission of the  application  to the said  Association's
office in the city wherein the  Building is situated (or the nearest  other city
having an Association  office).  The arbitrator shall hear the parties and their
evidence.  The decision of the arbitrator  shall be binding and conclusive,  and
judgment  upon the award or  decision  of the  arbitrator  may be entered in the
Superior Court of the Commonwealth of Massachusetts.  The parties consent to the
jurisdiction  of the Superior Court of the  Commonwealth  of  Massachusetts  and
further agree that any process or notice of motion or other  application  to the
Superior  Court or a Judge  thereof may be served  outside the  Commonwealth  of
Massachusetts by registered mail or

                   KBFIII/SOFTWARE DEVELOPER's COMPANY/5.1.96

by personal service,  provided a reasonable time for appearance is allowed.  The
costs and expenses of each arbitration hereunder and their apportionment between
the parties shall be determined by the  arbitrator in his award or decision.  No
arbitrable  dispute shall be deemed to have arisen under this Lease prior to (i)
the expiration of the period of twenty (20) days after the date of the giving of
written notice by the party asserting the existence of the dispute together with
a description thereof sufficient for an understanding  thereof; and (ii) where a
Tenant  payment is in issue,  the amount billed by Landlord  having been paid by
Tenant.

8.17 INABILITY TO PERFORM

This Lease and the  obligations  of Tenant to pay rent hereunder and perform all
the other covenants,  agreements,  terms, provisions and conditions hereunder on
the part of Tenant to be  performed  shall in no way be  affected,  impaired  or
excused because Landlord is unable to fulfill any of its obligations  under this
Lease or is unable to supply or is delayed in supplying any service expressly or
impliedly  to be  supplied  or is unable  to make or is  delayed  in making  any
repairs, replacement, additions, alterations,  improvements or decorations or is
unable to supply or is  delayed  in  supplying  any  equipment  or  fixtures  if
Landlord  is  prevented  or delayed  from so doing by reason of strikes or labor
troubles or any other similar or dissimilar cause whatsoever  beyond  Landlord's
reasonable  control,  including but not limited to,  governmental  preemption in
connection  with a  national  emergency  or by  reason  of any  rule,  order  or
regulation of any department thereof of any governmental  agency or by reason of
the  conditions  of supply and demand  which have been or are  affected  by war,
hostilities or other similar or dissimilar  emergency.  In each such instance or
inability of Landlord to perform,  Landlord shall exercise reasonable  diligence
to eliminate the cause of such inability to perform.

8.18 EXCULPATORY CLAUSE

Neither  Tenant or any person or entity  claiming  by,  through or under  Tenant
shall not  assert or seek to enforce  any claim or breach of this Lease  against
any of Landlord's  assets other than Landlord's  equity interest in the Building
and in the uncollected  rents,  issues and profits thereof,  and Tenant and such
parties shall look solely to such interest for the satisfaction of any liability
of  Landlord  or  Landlord's  agents  under  this Lease or  otherwise,  it being
specifically  agreed that in no event shall  Landlord  (or any of the  officers,
trustees,  directors,   partners,   beneficiaries,   joint  venturers,  members,
stockholders  or  other  principals,  agents  (including,   without  limitation,
Landlord's  managing agent for the Property) or  representatives,  and the like,
disclosed  or  undisclosed,  thereof)  ever by  personally  liable  for any such
liability.  This paragraph shall not limit any right that Tenant might otherwise
have to obtain  injunctive  relief against  Landlord or to take any other action
which  shall not  involve  the  personal  liability  of  Landlord  to respond in
monetary  damages from Landlord's  assets other than the Landlord's  interest in
the Building, as aforesaid.  In no event shall Landlord (or any of the officers,
trustees,  directors,   partners,   beneficiaries,   joint  venturers,  members,
stockholders  or  other  principals,  agents  (including,   without  limitation,
Landlord's  managing  agent for the Property) or  representatives  and the like,
disclosed or undisclosed,  thereof) ever be liable for consequential damages. If
by reason of  Landlord's  failure  to  complete  construction  of the  Premises,
Landlord  shall  be held  to be in  breach  of this  Lease,  Tenant's  sole  and
exclusive remedy shall be a right to terminate this Lease.

8.19 PARTIES BOUND - SEISIN OF TITLE

The covenants,  agreements, terms, provisions and conditions of this Lease shall
bind and benefit the  successors and assigns of the parties hereto with the same
effect as if mentioned

                  KBFIII/SOFTWARE DEVELOPER's COMPANY/5.1.96

   in each instance where a party hereto is named or referred to, except that no
   violation of the  provisions  of Section 5.6 hereof shall operate to vest any
   rights in any successor or assignee of Tenant and that the provisions of this
   Section  8.19 shall not be  construed  as  modifying  the default  provisions
   contained in Article VII hereof.

  If, in  connection  with or as a  consequence  of the sale,  transfer or other
  disposition of Landlord's interest in the Building or Property,  any party who
  is  Landlord  ceases  to be the  owner  of the  reversionary  interest  in the
  Premises,  Landlord shall be entirely freed and relieved from the  performance
  and observance  thereafter of all covenants and  obligations  hereunder on the
  part of Landlord to be performed and observed,  it being understood and agreed
  in such event (and it shall be deemed and construed as a covenant running with
  the  land)  that  the  person  succeeding  to  Landlord's  ownership  of  said
  reversionary  interest shall thereupon and thereafter  assume, and perform and
  observe, any and all of such covenants and obligations of Landlord.

                                   ARTICLE IX
                    RIGHTS OF PARTIES HOLDING PRIOR INTERESTS

  9.1 Lease Subordinate

  This Lease shall be subject and  subordinate  to any mortgage now or hereafter
  on the  Property or  Building,  or both,  which are  separately  and  together
  hereinafter in this Article IX referred to as "the mortgaged premises", and to
  each  advance  made or  hereafter  to be made under any  mortgage,  and to all
  renewals,  modifications,  consolidation,  replacements and extensions thereof
  and all substitutions  therefor,  provided that the holder thereof enters into
  an  agreement  with  Tenant by the terms of which  such  holder  will agree to
  recognize the rights of tenant under this Lease and to accept Tenant as tenant
  of the Premises  under the teens and  conditions of this Lease in the event of
  acquisition  of  title  by such  holder  through  foreclosure  proceedings  or
  otherwise  and Tenant will agree to recognize  the holder of such  mortgage as
  Landlord in such event,  which  agreement  shall be made expressly to bind and
  inure to the benefit of the successors and assigns of Tenant and of the holder
  and upon anyone  purchasing  the Premises at any  foreclosure  sale,  provided
  however,  that such holder  shall not:  (i) be liable for any  previous act or
  omission of Landlord under this Lease; (ii) be subject to any offset,  defense
  or  counterclaim  which  shall  theretofore  have  accrued  to Tenant  against
  Landlord;  (iii) have any  obligation  with  respect to any  security  deposit
  unless it shall have been paid over or physically delivered to such successor;
  or (iv) be bound by any previous modification of this Lease or by any previous
  payment of Annual  Fixed Rent for a period  greater  than one (1) month,  made
  without  the  consent of such  holder  where such  consent is  required by the
  applicable  instrument.  Notwithstanding  the foregoing any such holder may at
  its election  subordinate  its  mortgage to this Lease  without the consent or
  approval  of Tenant.  Tenant and  Landlord  agree to execute  and  deliver any
  appropriate  instruments  necessary to carry out the  agreements  contained in
  this Section 9.1. Tenant  acknowledges that, where applicable,  any consent or
  approval  hereafter given by Landlord may be subject to the further consent or
  approval of the holder; and the failure or refusal of such holder to give such
  consent or approval  shall,  notwithstanding  anything to the contrary in this
  Lease   contained,   constitute   reasonable   justification   for  Landlord's
  withholding its consent or approval. Tenant hereby irrevocably constitutes and
  appoints Landlord or any holder, and their respective  successors in interest,
  acting  singly,  Tenant's  attorney-in-fact  to execute  and  deliver any such
  certificate or instrument  for, on behalf and in the name of Tenant,  but only
  if Tenant fails to execute,  acknowledge  and deliver any such  certificate or
  instrument  within  ten ( 10) days  after  Landlord  or such  holder  has made
  written request therefor.

                   KBFIII/SOFTWARE DEVELOPER's COMPANY/5.1.96

9.2 RIGHTS OF HOLDER OF MORTGAGE  TO NOTICE OF DEFAULTS BY LANDLORD  AND TO CURE
    SAME

No act or failure to act on the part of  Landlord  which  would  entitle  Tenant
under the terms of this Lease, or by law, to be relieved of Tenant's obligations
hereunder or to terminate  this Lease,  shall result in a release or termination
of such  obligations or a termination of this Lease unless (i) Tenant shall have
first given  written  notice of  Landlord's  act or failure to act to Landlord's
mortgagees of record,  if any,  specifying  act or failure to act on the part of
Landlord  which  could or would give  basis to  Tenant's  rights;  and (ii) such
mortgagees  after  receipt of such notice,  have failed or refused to correct or
cure the  condition  complained  of within a  reasonable  time  thereafter;  but
nothing  contained in this Section 9.3 shall be deemed to impose any  obligation
on any such  mortgagees to correct or cure any condition.  "Reasonable  time" as
used above means and  includes a  reasonable  time to obtain  possession  of the
mortgaged  premises if the  mortgagee  elects to do so and a reasonable  time to
correct or cure the condition if such condition is determined to exist.

EXECUTED as a sealed  instrument in two or more counterparts on the day and year
first above written.

LANDLORD:

K/B Fund III

/s/ Mark F. Tassinari

Mark F. Tassinari
Vice President

Hereunto Duly Authorized

TENANT:

The Software Developer's Company, Inc.

/S/ Barry N. Bycoff

Barry N. Bycoff
President and Chief Executive Officer

Hereunto Duly Authorized 

Basic Info X:

Name: LEASE
Type: Lease
Date: June 28, 1996
Company: NETEGRITY INC
State: Delaware

Other info:

Date:

  • June 1 , 1996
  • July 1 , 1995
  • June 30 , 1996
  • January 1 , 1996
  • December 31 , 1996
  • thirty 30

Organization:

  • Koll Management Services , Inc. 60 State Street Boston
  • Tenant 3.2 Real Estate Taxes
  • Landlord 4.2 Additional Services Available to Tenant 4.3 Additional Air Conditioning Equipment
  • Rentable Floor Areas 8.2 Notice of Lease
  • Enforce 8.4 Acceptance of Partial Payments of Rent
  • Lease Subordinate 9.2 Rights of Holder of Mortgage to Notice of Defaults Landlords
  • Standard & Poor
  • Tenant for Operating Expenses Allocable
  • Tenant 's Operating Expense Base
  • Rentable Floor Area of Tenant
  • Term Commencement Date
  • Workmen 's Compensation Insurance
  • Automobile Liability Insurance
  • Landlord 's Services Landlord
  • National Board of Fire Underwriters
  • Landlord 's Original Address
  • Tenant 's Original Address
  • Landlord of Annual Fixed Rent
  • LYNCH MURPHY WALSH & PARTNERS
  • American Arbitration Association
  • Commonwealth of Massachusetts
  • Company , Inc.

Location:

  • Hingham
  • Tenant
  • Waltham
  • U.S.
  • Massachusetts

Money:

  • $ 95,040.00 $ 7,920.00 2
  • $ 100,800.00 $ 8,400.00
  • $ 16,885.00
  • $ 1.00
  • $ 5,000,000.00

Person:

  • Robert Tagliamonte
  • VIII
  • Mark F. Tassinari Mark F. Tassinari
  • Barry N. Bycoff Barry N. Bycoff

Percent:

  • 5 %
  • 100 %
  • 12 percentage points
  • fifty percent
  • 50 %