Exhibit 10.19

LEASE

BY AND BETWEEN

VEF III FUNDING, LLC

as Landlord

and

INTERLEAF, INC.
as Tenant

for premises located at
400 Fifth Avenue, Waltham, MA



---

Table of Contents



|          |              |                                                  |  |    |  | Page | 
|--------- | ------------ | ------------------------------------------------ |  | -- |  | ---- | 
|          |              |                                                  |  |    |  |      | 
|          |              |                                                  |  |    |  |      | 
|SECTION 1 |              | Reference Data                                   |  | 1  | 
|          | Section 1.1. | Reference Information                            |  | 1  | 
|          | Section 1.2. | Exhibits                                         |  | 3  | 
|          |              |                                                  |  |    |  |      | 
|SECTION 2 |              | Premises and Term                                |  | 4  | 
|          | Section 2.1. | Premises                                         |  | 4  | 
|          | Section 2.2. | Term                                             |  | 5  | 
|          | Section 2.3. | Option to Extend Term                            |  | 5  | 
|          | Section 2.4  | Right of First Offer On Available Space          |  | 5  | 
|          | Section 2.5  | Right of First Refusal On Second Floor Space     |  | 6  | 
|          |              |                                                  |  |    |  |      | 
|SECTION 3 |              | Construction                                     |  | 6  | 
|          | Section 3.1. | Premises As Is; Landlord's Work                  |  | 6  | 
|          | Section 3.2. | Preparation of Premises for Occupancy            |  | 7  | 
|          | Section 3.3. | Construction Representatives.                    |  | 7  | 
|          | Section 3.4. | Tenant Improvement Allowance                     |  | 8  | 
|          |              |                                                  |  |    |  |      | 
|SECTION 4 |              | Annual Rent                                      |  | 8  | 
|          | Section 4.1. | The Annual Rent                                  |  | 8  | 
|          | Section 4.2. | Market Rent                                      |  | 9  | 
|          |              |                                                  |  |    |  |      | 
|SECTION 5 |              | Operating Cost Escalation                        |  | 10 | 
|          | Section 5.1. | Operating Cost Escalation                        |  | 10 | 
|          | Section 5.2. | Estimated Operating Cost Escalation Payments     |  | 12 | 
|          | Section 5.3. | Real Estate Tax Escalation Payments              |  | 12 | 
|          |              |                                                  |  |    |  |      | 
|SECTION 6 |              | Insurance                                        |  | 13 | 
|          | Section 6.1. | Tenant's Insurance                               |  | 13 | 
|          | Section 6.2. | Landlord's Insurance                             |  | 14 | 
|          | Section 6.3. | Tenant Reimbursement of Certain Insurance Costs. |  | 14 | 
|          | Section 6.4. | Requirements Applicable to Insurance Policies.   |  | 14 | 
|          | Section 6.5. | Waiver of Subrogation                            |  | 15 | 
|          |              |                                                  |  |    |  |      | 
|SECTION 7 |              | Landlord's Covenants                             |  | 15 | 
|          | Section 7.1. | Quiet Enjoyment                                  |  | 15 | 
|          | Section 7.2. | Maintenance and Repair                           |  | 15 | 
|          | Section 7.3. | Exterior Common Areas and Facilities             |  | 16 | 
|          | Section 7.4. | Heating and Air Conditioning                     |  | 16 | 
|          | Section 7.5. | Electricity                                      |  | 16 | 
|          |              |                                                  |  |    |  |      | 

---



|           |                          |                                                      |  |  |    | Page | 
|---------- | ------------------------ | ---------------------------------------------------- |  |  | -- | ---- | 
|           |                          |                                                      |  |  |    |      | 
|           |                          |                                                      |  |  |    |      | 
|           | Section 7.6.             | Cleaning                                             |  |  |    | 17   | 
|           | Section 7.7.             | Interruptions                                        |  |  |    | 17   | 
|           | Section 7.8.             | Tenant's Access to Building                          |  |  |    | 18   | 
|           |                          |                                                      |  |  |    |      | 
|SECTION 8  | Tenant's Covenants       |                                                      |  |  | 18 |     
|           | Section 8.1.             | Use                                                  |  |  |    | 18   | 
|           | Section 8.2.             | Repair and Maintenance                               |  |  |    | 18   | 
|           | Section 8.3.             | Compliance with Law and Insurance
      Requirements |  |  |    | 19   | 
|           | Section 8.4.             | Tenant's Work                                        |  |  |    | 19   | 
|           | Section 8.5.             | Indemnity.                                           |  |  |    | 20   | 
|           | Section 8.6.             | Landlord's Access                                    |  |  |    | 20   | 
|           | Section 8.7.             | Alterations to Building                              |  |  |    | 21   | 
|           | Section 8.8.             | Personal Property at Tenant's Risk                   |  |  |    | 22   | 
|           | Section 8.9.             | Payment of Landlord's Cost of
      Enforcement.     |  |  |    | 22   | 
|           | Section 8.10.            | Yield Up                                             |  |  |    | 22   | 
|           | Section 8.11.            | Estoppel Certificate                                 |  |  |    | 22   | 
|           | Section 8.12.            | Landlord's Expenses Re Consents                      |  |  |    | 23   | 
|           | Section 8.13.            | Rules and Regulations                                |  |  |    | 23   | 
|           | Section 8.14.            | Holding Over.                                        |  |  |    | 23   | 
|           | Section 8.15.            | Assignment and Subletting                            |  |  |    | 23   | 
|           | Section 8.16.            | Overloading and Nuisance                             |  |  |    | 25   | 
|           |                          |                                                      |  |  |    |      | 
|SECTION 9  | Casualty or Taking       |                                                      |  |  | 25 |     
|           | Section 9.1.             | Termination                                          |  |  |    | 25   | 
|           | Section 9.2.             | Restoration                                          |  |  |    | 26   | 
|           | Section 9.3.             | Award                                                |  |  |    | 26   | 
|           |                          |                                                      |  |  |    |      | 
|SECTION 10 | Default                  |                                                      |  |  | 27 |     
|           | Section 10.1.            | Events of Default                                    |  |  |    | 27   | 
|           | Section 10.2.            | Remedies                                             |  |  |    | 28   | 
|           | Section 10.3.            | Remedies Cumulative                                  |  |  |    | 28   | 
|           | Section 10.4.            | Landlord's Right to Cure Defaults                    |  |  |    | 28   | 
|           | Section 10.5.            | Effect of Waivers of Default                         |  |  |    | 29   | 
|           | Section 10.6.            | No Accord and Satisfaction                           |  |  |    | 29   | 
|           | Section 10.7.            | Interest on Overdue Sums; Late Charge                |  |  |    | 29   | 
|           |                          |                                                      |  |  |    |      | 
|SECTION 11 | Mortgages                |                                                      |  |  | 30 |     
|           | Section 11.1.            | Rights of Mortgage Holders                           |  |  |    | 30   | 
|           | Section 11.2.            | Subordination and Attornment                         |  |  |    | 30   | 
|           | Section 11.3.            | Subordination of Mortgage                            |  |  |    | 31   | 
|           | Section 11.4.            | Provisions                                           |  |  |    | 31   | 
|           |                          |                                                      |  |  |    |      | 
|SECTION 12 | Miscellaneous Provisions |                                                      |  |  | 31 |     
|           | Section 12.1.            | Notices from One Party to the Other                  |  |  |    | 31   | 
|           | Section 12.2.            | Quiet Enjoyment                                      |  |  |    | 32   | 
|           | Section 12.3.            | Lease Not to be Recorded; Notice of
      Lease      |  |  |    | 32   | 





---

|               |  |                                                     |  |    | 
|-------------- |  | --------------------------------------------------- |  | -- | 
|Section 12.4.  |  | Bind and Inure; Limitation of Landlord's Liability. |  | 32 | 
|               |  |                                                     |  |    | 
|Section 12.5.  |  | Acts of God                                         |  | 32 | 
|               |  |                                                     |  |    | 
|Section 12.6.  |  | Landlord's Default.                                 |  | 32 | 
|               |  |                                                     |  |    | 
|Section 12.7.  |  | Brokerage                                           |  | 33 | 
|               |  |                                                     |  |    | 
|Section 12.8.  |  | Miscellaneous                                       |  | 33 | 
|               |  |                                                     |  |    | 
|Section 12.9.  |  | Security Deposit                                    |  | 33 | 
|               |  |                                                     |  |    | 
|Section 12.10. |  | Waiver of Trial By Jury                             |  | 35 | 
|               |  |                                                     |  |    | 
|Section 12.11. |  | No Surrender or Release                             |  | 35 | 
|               |  |                                                     |  |    | 
|Section 12.12. |  | No Representations                                  |  | 35 | 
|               |  |                                                     |  |    | 
|Section 12.13. |  | No Money Damages                                    |  | 35 | 
|               |  |                                                     |  |    | 
|Section 12.14. |  | Financial Statements                                |  | 36 | 
|               |  |                                                     |  |    | 
|Section 12.15. |  | Tenant's Signage                                    |  | 36 | 
|               |  |                                                     |  |    | 
|Section 12.16. |  | Operation of Cafeteria                              |  | 36 | 
|               |  |                                                     |  |    | 
|Section 12.17. |  | Renovation of Lobby and Cafeteria                   |  | 36 | 
|               |  |                                                     |  |    | 
|Section 12.18. |  | Rooftop Installations                               |  | 36 | 
|               |  |                                                     |  |    | 
|Section 12.19. |  | Generator Pad                                       |  | 37 | 
|               |  |                                                     |  |    | 
|Section 12.20. |  | Confidentiality Agreement                           |  | 37 | 

---

LEASE

SECTION 1

Reference Data

Section
1.1.    Reference Information. Reference in this Lease
to any of the following shall have the meaning set forth below:

Date of this Lease: March
__, 2000

Premises: The following
portions (shown on Exhibit A) of the building (the "Building") on the
lot (the "Lot") shown on Exhibit B, situated at 400 Fifth Avenue,
Waltham, MA: (a) a portion of the First Floor of the Building (the "First
Floor Premises"), (b) a portion of the Second Floor of the Building (the
"Second Floor Premises"), (c) the entire rentable square footage of the
Third Floor of the Building (the "Third Floor Premises") and (d) the entire
rentable square footage of the Fourth Floor of the Building (the "Fourth Floor
Premises"), all as shown on the plans attached hereto as Exhibit A. The First
Floor Premises is comprised of two components: (i) the area shown on Exhibit A-1
as the "First Floor First Stage Premises" and (ii) the area shown on Exhibit
A-1 as the "First Floor Second Stage Premises".

Landlord:    
VEF III Funding, LLC, a Delaware limited liability company

Address of Landlord:    
c/o Lend Lease Real Estate Investments, Inc.                                     
    
   101 Arch Street, Boston, MA 02110

Tenant: Interleaf, Inc.,
a Massachusetts corporation

Address of Tenant:    
Before Term Commencement Date: 62 Fourth Avenue, Waltham, MA                                     
   
 On and after Term Commencement Date: at the Premises

Landlord's Construction
Representative: Lynn Scarbo, Meredith & Grew Incorporated

Tenant's Construction
Representative: Kevin Fitzgibbon, Interleaf, Inc.

|Term Commencement Date: | (I) July 1, 2000 (the "Initial
      Term Commencement Date"), with respect to the Third Floor Premises,
      the Fourth Floor Premises, the - Second Floor Premises and the
      "First Floor First Stage Premises", and (II) the earlier of (i)
      the date that Tenant occupies the same for purposes of commencing its
      business
|----------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

1

---

|                         | operations or (ii) October 1, 2000 (such earlier date shall be
      referred to herein as the "First Floor Second Stage Premises Term
      Commencement Date) with respect to the "First Floor Second Stage
      Premises."
|------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|                         |                                                                                                                                                                                                                               
|Term:    See Section 2.2 |                                                                                                                                                                                                                               
|                         |                                                                                                                                                                                                                               
|Extension Term:          | One five (5) year period beginning on the first day after the
      expiration of the original term.                                                                                                                          



|Premises Square Footage: | First Floor Premises:        | Approximately 14,188 rentable square
      feet (of which the First Floor First Stage Premises consists of 8,603
      rentable square feet and the First Floor Second Stage Premises consists of
      5,585 rentable square feet)
|------------------------ | ---------------------------- | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|                         | Second Floor Premises:       | Approximately 12,229 rentable square feet                                                                                                                                                                                          
|                         | Third Floor Premises:        | Approximately 20,079 rentable square feet                                                                                                                                                                                          
|                         | Fourth Floor Premises:       | Approximately 20,079 rentable square feet                                                                                                                                                                                          
|                         |                              |                                                                                                                                                                                                                                    
|Building Square Footage: | 114,531 rentable square feet |                                                                                                                                                                                                                                    



|Annual Rent: | (a) | For the period (the "First Initial Rental Period")
      beginning on the Initial Term Commencement Date and ending on the day
      before the First Floor Second Stage Premises Term Commencement Date:
|------------ | --- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

$1,646,730 per annum
($137,227.50 per month)

| | (b) | For the period (the "Second Initial Rental Period")
      beginning on the first day after the end of the First Initial Rental
      Period and ending on the day before the third anniversary of the Initial
      Term Commencement Date:
| | --- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

$1,797,525 per annum
($149,793.75 per month)

| | (c) | For the period beginning on the first day after the expiration
      of the Second Initial Rental Period and continuing for a period of three
      years and three months:
| | --- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------

2

---

$ 1,930,675 per annum 
($160,889.58 per month)

| | Notwithstanding the above: (i) Tenant shall not be obligated to
      make the payments of Annual Rent due for the ninety (90) day period
      commencing on the Initial Term Commencement Date with respect to the
      Second Floor  Premises, the Third Floor Premises, the Fourth Floor
      Premises and the First Floor First Stage Premises; and (ii) the monthly
      payments of Annual Rent for the first three (3) months of the Second
      Initial Rental Period for the Premises shall be abated by $12,566.25 per
      month.
| | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   

|Annual Base Operating Costs: | An amount equal to Landlord's Operating Costs (as defined in
      Section 5.1 of the Lease) for calendar year 2001.                                                   
|---------------------------- | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------
|                             |                                                                                                                                                                        
|Tax Base Amount:             | An amount equal to Landlord's Tax Expenses Allocable to the
      Premises (as defined in Section 5.3 of the Lease) for the tax fiscal year
      ending June 30, 2002.
|                             |                                                                                                                                                                        

|Tenant's Estimated Electrical Charge: | $66,575 per annum
|------------------------------------- | -----------------

Permitted Uses: For general office purposes.

|Public Liability Insurance Limit: | Combined single limit of $5,000,000, or greater amount as
      reasonably required by Landlord from time to time.
|--------------------------------- | ------------------------------------------------------------------------------------------------------------------

Tenant's Proportionate Fraction:     58.13%

Security Deposit:    $1,100,506.50

|Broker: | Meredith & Grew Incorporated and Cushman & Wakefield of
      Massachusetts, Inc.
|------- | ---------------------------------------------------------------------------------

Section 1.2.Exhibits.     The following
Exhibits are attached to and incorporated in this Lease:

Exhibit A: Plans of Premises
                   
Exhibit B: Description of Lot 
                   
Exhibit C: Parking Area 
                   
Exhibit D: Cleaning Specifications 
                   
Exhibit E: Rules and Regulations 
                   
Exhibit F: DOME Right of First Offer Space

3

---

SECTION2Premises and Term

Section 2.1.     Premises. Landlord hereby
leases and demises the Premises to Tenant and Tenant hereby leases the Premises
from Landlord, subject to any and all existing encumbrances and other matters of
record and subject to the terms and provisions of this Lease, excepting and
reserving to Landlord the exterior walls of the Building and further reserving
to Landlord the right to place above the dropped ceiling and/or below the floor
in the Premises and behind the perimeter walls of the Premises utility lines,
pipes, equipment and the like, to serve premises other than the Premises, and to
replace and maintain and repair such utility lines, pipes, equipment and the
like in, over and upon the Premises as may have been or may be installed by
Landlord in the Building. To the extent that the City of Waltham shall require
the same, Landlord also reserves the right, on behalf of the other tenants and
occupants of the Building, to utilize and to grant to such tenants and occupants
and the parties referred to in the next sentence the right to utilize a portion
or portions (collectively the "Emergency Access Portion") of the First Floor
Second Stage Premises as shall be necessary in Landlord's reasonable
discretion as a means of secondary access and egress to and from the Building
for fire emergency purposes in the case of a potential fire and the resulting
activation of the fire alarm for the Building. To the extent that such means of
secondary access and egress via the Emergency Access Portion shall be required
by the City of Waltham, Landlord and its tenants and other occupants of the
Building and the employees, agents, contractors and invitees of such tenants and
occupants shall be entitled to utilize the Emergency Access Portion for
emergency fire access and egress purposes only. If such Emergency Access Portion
shall be so utilized, Landlord shall install and maintain, at Landlord's
expense, electronic or magnetic locking devices on the doors for the Emergency
Access Portion that causes such doors to automatically delock when the fire
alarm for the Building is activated due to a potential fire and shall have the
right to install any necessary devices so as to connect the same with
Landlord's emergency fire alarm system.

The Premises are leased together with the right of Tenant to use the
parking areas located on the Lot, in such locations thereon as are designated
from time to time by Landlord, for parking (free of a usage charge) by its
customers, employees, suppliers and visitors, in common with others from time to
time entitled thereto (said parking areas and locations being identified on the
plan attached hereto as Exhibit "C"). Tenant's rights to use the parking
areas, however, shall be limited to 3.3 spaces per 1,000 square feet of rentable
square footage of the Premises. Tenant's usage of such number of parking
spaces shall be on an unassigned and unreserved basis. Landlord shall have the
right to monitor Tenant's usage of such parking spaces and Landlord shall have
the right to establish reasonable rules and regulations with respect to the
usage of such parking spaces. Landlord reserves the right from time to time, and
at Landlord's sole discretion and after written notice, to alter, reduce or
redesign the parking area and to temporarily close portions of the parking area,
or to relocate the ingress and egress to and from the parking area and the
Building; provided, however, that Landlord's actions shall not result in a
permanent diminution of the number of parking spaces Tenant is entitled to use
hereunder. Notwithstanding any supervision or control over any parking area on
the Lot which Landlord may undertake pursuant to this Lease or otherwise, Tenant
acknowledges

4

---

and agrees that Landlord shall not be responsible or obligated
hereunder to furnish any security or security services to any parking areas.

Tenant and its
employees shall also have the right to use, in common with others entitled
thereto, the hallways, stairways, and elevator(s), if any, necessary for access
and egress to the Premises and other common areas of the Building.

Section
2.2.     Term.     TO HAVE
AND TO HOLD for a term (hereinafter such term plus any extensions hereof shall
be referred to herein as the "term" or "Term") beginning on July 1, 2000
(the "Term Commencement Date") and continuing for a period of six (6) years
and three (3) months (the "original term").

Section
2.3.     Option to Extend Term.    
Tenant shall have the option to extend the term of this Lease beyond the
original term for the Extension Term, provided (i) no default in the obligations
of Tenant under this Lease shall exist at the time such option is exercised or
as of the first day of the Extension Term; (ii) the original Tenant itself (or
"BroadVision" [as such entity is defined herein]) shall be in occupancy of
at least 75% of the Premises as of the first day of the Extension Term; and
(iii) Tenant shall give notice to Landlord of its exercise of such option not
less than one (1) year prior to expiration of the original term. All of the
terms and provisions of this Lease shall be applicable during the Extension Term
except that (a) Tenant shall have no option to extend the term of the Lease
beyond the Extension Term and (b) Annual Rent for the Extension Term shall be
the Market Rent, as defined in Section 4.2, as of the first day of the Extension
Term but in no event less than the per annum Annual Rent in effect in the last
full year of the original term.

Section 2.4        
Right of First Offer On Available Space. Commencing as of the date after
the Term Commencement Date on which the Building is 100% leased to tenants and
continuing until the date which is three (3) years prior to the last day of the
original term, subject to the rights of existing tenants to lease such space,
and provided that (i) the original Tenant itself (or Broadvision) is in
occupancy of at least 70% of the Premises at the time of Tenant's notice under
this Section 2.4; and (ii) no default in the obligations of Tenant hereunder
shall exist at the time of Tenant's notice under this Section 2.4, in the
event that any space in the Building shall become available for leasing to any
tenant (other than the then existing tenant of such space), prior to marketing
such space, Landlord shall give Tenant notice of the availability of such space
and the rent and other terms and conditions on which Landlord is willing to
lease such space. Without limiting the generality of the foregoing sentence,
Tenant recognizes and agrees that DOME imaging systems, inc. ("DOME"), an
existing tenant of the Building, shall have, until such time as the "DOME
Right of First Offer Space" shall have been hereafter leased under a new lease
to a third party, a superior right of first offer on that approximately 5,154
rentabl e square feet of space located on the fifth floor of the Building shown
on Exhibit F hereto as the "DOME Right of First Offer Space". If DOME
exercises its right of first offer to lease the DOME Right of First Offer Space,
however, Tenant's right of first offer to lease the DOME Right of First Offer
Space

5

---

shall not arise prior to the date that the term of Landlord's
lease with DOME for such DOME Right of First Offer Space (including any
extensions of such term) expires or is sooner terminated.

If (a) Tenant shall
not give Landlord notice of Tenant's desire to lease the space identified in
Landlord's notice under the prior paragraph within ten (10) days after
Landlord's notice or (b) Landlord and Tenant shall not execute and deliver an
amendment to this Lease adding such space to the Premises in a mutually
acceptable form within twenty (20) days after Tenant gives such notice, Landlord
shall be free to lease such space to any other party at any time and from
time-to-time thereafter on such terms as Landlord shall determine.

Section 2.5    
Right of First Refusal On Remaining Second Floor Space. Provided that (i)
no sublease or subleases shall be in effect at the time of Tenant's notice
under this Section 2.5; and (ii) no default in the obligations of Tenant
hereunder shall exist at the time of Tenant's notice under this Section 2.5,
in the event that Landlord enters into a letter of intent with another party
prior to July 1, 2000 for the remaining (i.e., exclusive of the Second Floor
Premises leased to Tenant under this Lease) space on the second floor of the
Building, prior to consummating a lease pursuant to such letter of intent (the
"Second Floor Letter of Intent"), Landlord shall give Tenant notice of the
Second Floor Letter of Intent whereupon Tenant shall have the right to lease all
(but not just a portion) of the space described in the Second Floor Letter of
Intent on the same terms applicable to the Premises, subject to the next
sentence. If (a) Tenant shall not give Landlord notice of Tenant's desire to
lease the space described in the Second Floor Letter of Intent on the same terms
applicable to the Premises hereunder within three (3) business days after
Landlord's notice or (b) Landlord and Tenant shall not execute and deliver an
amendment to this Lease adding such space to the Premises in a mutually
acceptable form within fifteen (15) days after Tenant gives such notice,
Landlord shall be free to lease such space to the party identified in the Second
Floor Letter of Intent.

SECTION3Construction

Section 3.1Premises As Is; Landlord's Work. Except for
Landlord's obligation to perform the work described on Schedule 1 hereto
("Landlord's Work"), the Premises shall be leased to Tenant in "as is"
condition without any further obligation on the part of Landlord to perform any
construction therein or to prepare the same for Tenant's occupancy or
otherwise. Landlord's Work shall be completed in a good and workmanlike manner
employing materials of good quality and so as to conform with all applicable
building, fire, health and other codes, regulations, ordinances and laws, and
with all applicable insurance regulations. Upon the completion of Landlord's
Work, Tenant shall have the right to perform, at Tenant's sole cost and expense,
an air quality test(s) of the Premises, and upon the completion of such test(s),
Tenant shall provide a copy of the results of such test(s) to Landlord. Any
alterations, improvements, additions or construction to the Premises proposed by
Tenant shall be subject to Section 8.4 of this Lease. Without limiting the
generality of the prior sentence,

6

---

Tenant shall not perform any of such proposed work prior to the date
on which Landlord's Work shall have been substantially completed.

Section 3.2.    
Preparation of Premises for Occupancy. Landlord agrees to use reasonable
efforts to substantially complete construction of Landlord's Work for the
Third Floor Premises, the Fourth Floor Premises and the First Floor First Stage
Premises on or before May 15, 2000 and, with respect to the First Floor Second
Stage Premises, within forty-five (45) days after the existing tenant (i.e., as
of the date of this Lease) vacates the same in its entirety (which vacation date
is currently scheduled for June 30, 2000). Without limiting the provisions of
the prior sentence, the times for completion of construction of Landlord's
Work shall be extended by the duration of any delay referred to in Section 12.5
and by the duration of any delays caused by any of the existing tenants in
failing to vacate the same on the dates scheduled for such vacation. If for any
reason Landlord does not deliver possession of the Third Floor Premises, the
Fourth Floor Premises and the First Floor First Stage P remises to Tenant by the
Initial Term Commencement Date (unless such failure is caused by Tenant), all
rent and other payments due hereunder shall be proportionately abated until
delivery of such space in order to reflect the space not so delivered. If for
any reason Landlord does not deliver possession of the First Floor Second Stage
Premises by the First Floor Second Stage Premises Term Commencement Date (unless
such failure is caused by Tenant) the rent and other payments for the First
Floor Second Stage Premises shall be abated until delivery of such space to
Tenant. Notwithstanding the provisions of this paragraph, if Landlord shall fail
for any reason to deliver possession of any portion of the Premises by December
31, 2000, Tenant shall have the right to terminate this Lease by notice given to
Landlord on or before January 10, 2001 but only as to the portion not so
delivered by December 31, 2000, and not as to any other portions delivered prior
to December 31, 2000; provided, however, that if Landlord shall fail to deliver
for any reason possession of at least 25% of the Premises by December 31, 2000,
Tenant shall have the right to terminate the entire Lease by notice given to
Landlord on or before January 10, 2001.

Landlord's Work
for a particular floor of the Premises shall be deemed substantially complete on
the date on which construction of the same shall have been substantially
completed in accordance with Schedule 1 (with the exception of items that can be
completed without material interference to Tenant's construction work), as
reasonably certified by Landlord's contractor.

Landlord warrants that it
has good and legal title to the premises, the Building and Lot and has full
authority to enter into this Lease and demise the premises to Tenant.

Section 3.3.    
Construction Representatives. Each party authorizes the other to rely in
connection with plans and construction upon approval and other actions on the
party's behalf by any Construction Representative of the party named in Section
1.1 or any person hereafter designated in substitution or addition by notice to
the party relying.

Section
3.4.     Tenant Improvement
Allowance. Landlord shall provide Tenant with a tenant improvement allowance
in an amount not exceeding $798,900 in the aggregate (the

7

---

"Allowance") to reimburse Tenant for the costs incurred by
Tenant in performing initial leasehold improvements to the Premises and for the
other items described below in this Section 3.4, including but not limited to
architectural and engineering consulting costs, moving costs, telecommunications
equipment and installations and the purchase of office furniture, but subject,
however, to the limitations described in the next paragraph.

The Allowance shall
be paid to Tenant (in increments of not less $50,000), upon the submission to
Landlord of a written requisition with copies of invoices supporting the costs
sought to be reimbursed and, if applicable, (a) lien waivers from Tenant's
contractors and (b) a certificate from Tenant's architect certifying to the
completion of the percentage of work sought to be reimbursed. Landlord shall pay
each such approved requisition within twenty (20) days of its receipt.
Notwithstanding the foregoing, Landlord shall only be obligated to pay such
requisition submitted by Tenant up to the aggregate amount of the Allowance and
only to the extent that the amount described in such requisition shall be
included in the budget for Tenant's work that has been approved in writing by
Landlord prior to May 15, 2000. At least 50% of the Allowance shall be expended
for permanent leasehold improvements to the Premises, telecommunications wirin
g, equipment and installations, and architectural and engineering costs, and no
more than 50% of the Allowance shall be expended for moving costs, the purchase
of office furniture and other consultants' costs.

In no event,
however, shall Landlord be obligated (i) to make any payments to Tenant on
account of the Allowance prior to the Term Commencement Date or (ii) to make any
payments to Tenant on account of the Allowance for requisitions received from
Tenant after January 1, 2001, except if Tenant's failure to submit a
requisition prior to January 1, 2001 shall be due to Landlord's inability to
deliver any portion of the Premises by November 1, 2000.

SECTION4Annual Rent

Section
4.1.     The Annual Rent. Tenant shall pay rent
to Landlord at the Address of Landlord or at such other place or to such other
person or entity as Landlord may by notice to Tenant from time to time direct,
at the Annual Rent set forth in Section 1, in equal installments equal to 1/l2th
of the Annual Rent in advance on the first day of each calendar month included
in the term, and for any portion of a calendar month at the beginning or end of
the term, at that rate payable in advance for such portion.

Section 4.2.Market Rent. "Market Rent" shall be
computed as of the applicable date at the then current rentals being charged to
new or renewal tenants for comparable first class office space located in the
vicinity of the Building, taking into account and giving effect to, in
determining comparability, without limitation, such considerations as size,
location and lease term building quality and tenant improvement allowance.

Landlord shall
initially designate the Market Rent and shall furnish data in support of such
designation within forty-five (45) days from receipt of Tenant's notice of its
exercise

8

---

of its option to extend under Section 2.3, except that Landlord
shall not be obligated to provide such designation any sooner than the first day
of the eleventh (11th) month prior to the
commencement of the Extension Term. If Tenant disagrees with Landlord's
designation of the Market Rent, then Tenant shall have the right, by written
notice given within twenty-one (21) days after Tenant has been notified of
Landlord's designation, to submit such Market Rent to arbitration as follows:
Market Rent shall be determined by arbitrators, one to be chosen by Tenant, one
to be chosen by Landlord and a third to be selected, if necessary, as below
provided. Each arbitrator hereunder shall be an MAI-appraiser having at least
ten (10) years' experience in appraising rental values for space in properties
similar to the Building within a ten (10) mile radius of the Building. If within
twenty-one (21) days after Tenant's notice, the parties agree upon a single
arbitrato r, Market Rent shall be determined by such arbitrator. The unanimous
written decision of the two first chosen without selection and participation of
a third arbitrator, or otherwise the written decision of a majority of the three
arbitrators chosen and selected as provided herein, shall be conclusive and
binding upon Landlord and Tenant. Landlord and Tenant shall each notify the
other of its chosen arbitrator within twenty-one (21) days following the call
for arbitration and, unless such two arbitrators shall have reached a unanimous
decision within thirty (30) days after their designation, then they shall so
notify the then President of the Boston Bar Association and request him or her
to select an impartial third qualified arbitrator (having the qualifications
described above) to determine Market Rent as herein defined. Such third
arbitrator and the first two chosen shall hear the parties and their evidence
and render their decision within thirty (30) days following the conclusion of
such hearing and no tify Landlord and Tenant thereof. Landlord and Tenant shall
bear the expense of the third arbitrator (if any) equally. If the dispute
between the parties as to Market Rent has not been resolved before the
commencement of Tenant's obligation to pay rent under the Lease in Market Rent,
then Tenant shall pay rent under the Lease in respect of the premises based upon
the Market Rent designated by Landlord until either the agreement of the parties
as to the Market Rent or the decision of the arbitrators, as the case may be, at
which time Tenant shall pay any underpayment of rent to Landlord, or Landlord
shall refund any overpayment of rent to Tenant.

SECTION5Operating Cost Escalation

Section 5.1.Operating Cost Escalation. Tenant shall pay to
Landlord, as Additional Rent, Operating Cost Escalation (as defined below) on or
before the 20th day following receipt by Tenant of Landlord's Statement (as
defined below). After the end of each calendar year during the Term and after
Lease termination, Landlord shall render a statement ("Landlord's
Statement") in reasonable detail and according to generally accepted
accounting practices, certified by Landlord, and showing for the preceding
calendar year or fraction thereof, as the case may be, all of Landlord's
operating costs for the Building and Lot ("Landlord's Operating Costs"),
including, without limitation, premiums for insurance; compensation and all
fringe benefits, worker's compensation, insurance premiums and payroll taxes
paid by Landlord to, for or with respect to all persons engaged in the
operating, maintaining or cleaning of the Building (including the Premises) and
Lot; costs of electricity in ex cess of Tenant's Estimated Electrical Charge

9

---

and other Estimated Electrical Charges paid by other tenants of the
Building including, without limitation, costs of electricity furnished to the
Premises and other tenants' premises but excluding electricity separately
metered to Tenant or tenants; all other utility charges not billed directly to
tenants by Landlord or the utility company; all payments to contractors under
service contracts for operating, managing, cleaning, maintaining and repairing
the Building (including the Premises) and Lot (which payments may be to
affiliates of Landlord, provided the same are at comparable market rates); costs
of Building and cleaning supplies and equipment; if the Building shares common
areas or facilities with another building or buildings, the Building's allocable
share (as reasonably determined by Landlord in accordance with generally
accepted accounting principles) of the cost of cleaning, operating, managing
(including the cost of the management office for such buildings and facilities),
maintaining and repairing such common areas and facilities; and all other
reasonable and necessary expenses paid in connection with the cleaning,
operating, managing, maintaining, and repairing of the Building and Lot, or
either, and properly chargeable against income; it being agreed that if Landlord
shall install a new or replacement capital item for the purpose of complying
with applicable laws or regulations or intending to reduce Landlord's Operating
Costs, the annual amortization (determined by Landlord in accordance with
generally accepted accounting principles) of the cost thereof, with interest
thereon at the prime rate published in The Wall Street Journal from time
to time, shall be included in Landlord's Operating Costs.

Notwithstanding anything to the
contrary contained above, Landlord's Operating Costs shall not include costs and
expenses related to the following:

|(1) |  | Interest and amortization on mortgages for the Building
      and Lot;                                                                                                                                                                
|--- |  | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|    |  |                                                                                                                                                                                                                                       
|(2) |  | The cost of special services rendered to tenants
      (including Tenant) for which a special separate charge is made;                                                                                                                
|    |  |                                                                                                                                                                                                                                       
|(3) |  | Cost of restoration or replacements occasioned by fire
      or other casualty or caused by the exercise of eminent domain takings to
      the extent that Landlord receives insurance or eminent domain proceeds for
      the same;
|    |  |                                                                                                                                                                                                                                       
|(4) |  | The depreciation or amortization of the Building, or any
      part thereof;                                                                                                                                                          
|    |  |                                                                                                                                                                                                                                       
|(5) |  | Legal or professional fees relating to leasing or
      financing of the Building;                                                                                                                                                    
|    |  |                                                                                                                                                                                                                                       
|(6) |  | Promotional, advertising or marketing expenses; and                                                                                                                                                                                   
|    |  |                                                                                                                                                                                                                                       
|(7) |  | Capital expenditures, except to the extent referenced
      above in this Section 5.1.                                                                                                                                                

In determining Landlord's
Operating Costs, if (i) less than 95% of the Building shall have been occupied
by tenants and fully used by them, at any time during the year, Landlord's
Operating Costs shall be extrapolated to an amount equal to the like operating
expenses that would normally be expected to be incurred had such occupancy been
95%

10

---



and had such full utilization been made during the entire period, or (ii)
Landlord is not furnishing any particular work or service (the cost of which, if
performed by the Landlord, would be included in Landlord's Operating Costs) to a
tenant who has undertaken to perform such work or service in lieu of the
performance thereof by Landlord, Landlord's Operating Costs shall be deemed for
the purpose of this Section 5.1 to be increased by an amount equal to the
additional expense that would reasonably have been incurred during such period
by Landlord if it had at its own expense furnished such work or service to such
tenant.

"Operating Cost
Escalation" shall be equal to Tenant's Proportionate Fraction of the
excess, if any, of:

|(a) |  | Landlord's Operating Costs as indicated by Landlord's
      Statement; over
|--- |  | ---------------------------------------------------------------------------
|    |  |                                                                            
|(b) |  | The Annual Base Operating Costs.                                           

Notwithstanding the above
calculation, in no event shall Operating Cost Escalation be less than zero.

Notwithstanding any other
provision of this Section 5.1, if the Term expires or is terminated as of a date
other than the last day of a calendar year, then for such fraction of a calendar
year at the end of the Term, Tenant's last payment to Landlord under this
Section 5.1 shall be made on the basis of Landlord's best estimate of the items
otherwise includable in Landlord's Statement and shall be made on or before the
later of (a) 20 days after Landlord delivers such estimate to Tenant, or (b) the
last day of the Term, with an appropriate payment or refund to be made upon
submission of Landlord's Statement.

Within ninety (90) days after
receipt of each Landlord's Statement, Tenant or its agent (but in no event
shall such agent be a party or entity whose compensation is based in part or in
whole on the amount of discrepancies found) shall have the right to examine
Landlord's records relating to Landlord's Operating Costs described in such
applicable Landlord's Statement. Landlord shall make all its records relating
to the calculation of Landlord's Operating Costs available to Tenant or its
agents at reasonable times and upon reasonable advance notice at the Address of
Landlord or at the address of Landlord's property manager. Any errors shall be
promptly corrected, and any resulting overpayment by Tenant will be credited by
Landlord against Tenant's next payment(s) under Section 5.1, and any resulting
underpayment by Tenant will be promptly paid by Tenant. If Tenant shall perform
such examination for a particular period to which a particular Landlord's
Statement relates and it shall be found that Landlord's Operating Costs were
overstated in such Landlord's Statement by more than 7%, then Landlord shall
also be responsible to pay for Tenant's reasonable costs of performing such
examination. In the event that Tenant fails to complete such examination of
Landlord's records within such ninety (90) day period described above and
notify Landlord in writing of any discrepancies discovered within ten (10) days
after completing such examination, Tenant shall be estopped from raising any
claims with respect to the items set forth in the

11

---

applicable Landlord's Statement for the calendar year to which the
applicable Landlord's Statement relates.

Section 5. 2.   
Estimated Operating Cost Escalation Payments . If, with respect to any
calendar year or fraction thereof during the Term, Landlord reasonably estimates
that Tenant shall be obligated to pay Operating Cost Escalation, then Tenant
shall pay, as Additional Rent, on the first day of each month of such calendar
year and each ensuing calendar year thereafter, estimated monthly escalation
payments equal to 1/12th of the estimated Operating Cost Escalation for the
respective calendar year, with an appropriate additional payment, credit or
refund to be made within thirty (30) days after Landlord's Statement is
delivered to Tenant. Landlord may adjust such estimated monthly escalation
payment from time to time and at any time during a calendar year, and Tenant
shall pay, as Additional Rent, on the first day of each month following receipt
of Landlord's notice thereof, the adjusted estimated monthly escalation payment
and, on the first of the first month following receipt of Landlord's notice
thereof, any deficiency in prior payments made by Tenant prior to such
adjustment by Landlord in such calendar year.

Section 5.3.   If
with respect to any Tax Year (hereinafter defined) falling within the Term or
fraction of a Tax Year falling within the term at the beginning or end thereof,
Landlord's Tax Expenses Allocable to the Premises (hereinafter defined) for a
full Tax Year exceed the Tax Base Amount, or for any such fraction of a Tax Year
exceed the corresponding fraction of the Tax Base Amount, then, on or before the
thirtieth (30th) day following the receipt by Tenant of the certified statement
referred to below in this Section 5.3, Tenant shall pay to Landlord, as
Additional Rent, the amount of such excess less the monthly estimated payments
paid for such corresponding period pursuant to the last paragraph of this
Section 5.3.

Terms used herein are defined as
follows:

> (i)   "Tax
>   Year" means the twelve-month period beginning July l each year during the
>   term, or if the appropriate governmental tax fiscal period shall begin on any
>   other date than July l, such other date.
>   (ii)   "Landlord's
>   Tax Expenses for the Building and Lot" with respect to any Tax Year means
>   the aggregate real estate taxes on the Building or Lot with respect to that
>   Tax Year, reduced by any abatement receipts with respect to that Tax Year.
>   (iii)   
>   "Landlord's Tax Expenses Allocable to the Premises" means Tenant's
>   Proportionate Fraction of Landlord's Tax Expenses for the Building and Lot.

The term "real estate
taxes" as used herein shall mean all taxes, assessments (special,
betterment or otherwise, plus any interest thereon), levies, fees, water and
sewer rents and charges, and all other government levies and charges, general
and special,

12

---

ordinary and extraordinary, foreseen and unforeseen, which are allocable to
the term hereof and imposed or levied upon or assessed against the Lot or
Building or any rent or other sums payable by any tenants or occupants thereof.
Nothing herein shall, however, require Tenant to pay any income taxes, excess
profits taxes, excise taxes, franchise taxes, estate, succession, inheritance or
transfer taxes, provided, however, that if at any time during the term the
present system of ad valorem taxation of real property shall be changed so that
in lieu of the whole or any part of the ad valorem tax on real property, or in
lieu of increases therein, there shall be assessed on Landlord a capital levy or
other tax on the gross rents received with respect to the Building or Lot 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)
measured by or based, in whole or in part, upon gross rents, then any and all of
such taxes, assessments, levies or charges, to the extent so measured or based
("Substitute Taxes"), shall be included as real estate taxes
hereunder, provided, however, that Substitute Taxes shall be limited to the
amount thereof as computed at the rates that would be payable if the Building
and Lot were the only property of Landlord.

Landlord shall, upon receipt of
the applicable tax bills, render to Tenant a statement certified by Landlord
setting forth the amount of Tenant's Additional Rent for real estate taxes in
the event Landlord's real estate taxes Allocable to the Premises exceed the Tax
Base Amount. To the extent that Tax Expenses shall be payable to the taxing
authority in installments with respect to periods less than a Tax Year, the
foregoing statement shall be rendered and payments made on account of such
installments and computations shall be based upon appropriate prorations of
Landlord's Tax Expenses for the Building and Lot and the Tax Base Amount.

Notwithstanding the
foregoing and with respect to any Tax Year or fraction of a Tax Year falling
within the Term, Tenant shall pay to Landlord, as Additional Rent, on each
payment date for Annual Rent, an amount in respect of real estate taxes
determined by subtracting 1/12th of the Tax Base Amount for such Tax Year or
fraction of a Tax Year from 1/12th of Landlord's estimate, based on the most
current tax bills, of Landlord's Tax Expenses Allocable to the Premises for such
Tax Year or fraction of a Tax Year, with an appropriate adjustment within thirty
(30) days after delivery of Landlord's statement referred to in this Section
5.3. Landlord may adjust such estimated monthly escalation payment for real
estate taxes from time to time and at any time during a calendar year, and
Tenant shall pay, as Additional Rent, on the first day of each month following
receipt of Landlord's notice thereof, the adjusted estimated monthly escalation
payment and, on the first of the first month following receipt of Landlord's
notice thereof, any deficiency in prior payments made by Tenant prior to such
adjustment by Landlord in such calendar year.

SECTION 6Insurance.

Section 6.1.   
Tenant's Insurance.  Tenant shall, as Additional Rent, maintain
throughout the Term the following insurance:

13

---

(a)    Commercial
general liability insurance for any injury to person or property occurring on
the Premises, naming as insureds Tenant, Landlord and such persons, including,
without limitation, Landlord's property manager, as Landlord shall reasonably
designate from time to time, in amounts which shall, at the beginning of the
Term, be at least equal to the limits set forth in Section 1, and, from time to
time during the term, shall be for such higher limits as are reasonably required
by Landlord; and

(b)    Worker's
compensation insurance with statutory limits covering all of Tenant's employees
working at the Premises.

Section 6.2.   
Landlord's Insurance.  Landlord shall maintain throughout the Term
the following insurance and shall include the costs thereof in Landlord's
Operating Costs:

(a)    Commercial
general liability insurance for any injury to person or property occurring in
the common areas of the Lot or Building, in such amounts and with such
deductibles as Landlord may consider appropriate in its commercially reasonable
judgment;

(b)    All risk
fire and casualty insurance on a replacement value, agreed amount basis,
together with rental loss coverage and, if Landlord so elects, flood coverage to
the extent the same is available, insuring the Building and its rental value,
with such deductibles, if any, as Landlord shall consider appropriate in its
commercially reasonable judgment; and

(c)    At
Landlord's option, insurance against loss or damage from sprinklers and from
leakage or explosions or cracking of boilers, pipes carrying steam or water, or
both, pressure vessels or similar apparatus, in the so-called "broad
form", in such amounts and with such deductibles as Landlord may consider
appropriate, and insurance against such other hazards and in such amounts as may
from time to time be required by any bank, insurance company or other lending
institution holding a mortgage on the Building.

Section 6.3.   
Tenant Reimbursement of Certain Insurance Costs.  Tenant shall
reimburse Landlord for all of Landlord's costs incurred in providing such
insurance to the extent attributable to any special endorsement or increase in
premium resulting from the business or operations of Tenant or any special or
extraordinary hazards resulting therefrom. Landlord agrees to use reasonable
efforts to notify Tenant in advance of any anticipated additional insurance
premiums resulting from Tenant's specific use of the Premises or the Lot. If
any increase in the cost of Landlord's insurance is specifically attributable
to any other tenant's business at the Building, such increased insurance costs
shall be paid by such tenant and shall not be included in Landlord's Operating
Costs.

Section 6.4.   
Requirements Applicable to Insurance Policies.  All policies for
insurance required under the provisions of Section 6.1 shall be obtained from
responsible companies qualified to do business in the Commonwealth of
Massachusetts and in good

14

---

standing therein, which companies and the amount of insurance allocated
thereto shall be subject to Landlord's approval and Landlord's lender's
approval. Tenant agrees to furnish Landlord with insurance company certificates
of all such insurance and copies of the policies therefor prior to the beginning
of the Term hereof and of each renewal policy at least thirty (30) days prior to
the expiration of the policy it renews. Each such policy shall be noncancellable
with respect to the interest of Landlord and such mortgagees without at least
thirty (30) days' prior written notice thereto.

Section 6.5.   
Waiver of Subrogation.  All insurance which is carried by either
party with respect to the Premises or to furniture, furnishings, fixtures or
equipment therein or alterations or improvements thereto, whether or not
required, shall include provisions which either designate the other party as one
of the insured or deny to the insurer acquisition by subrogation of rights of
recovery against the other party to the extent such rights have been waived by
the insured party prior to occurrence of loss or injury, insofar as, and to the
extent that such provisions may be effective without making it impossible to
obtain insurance coverage from responsible companies qualified to do business in
the Commonwealth of Massachusetts (even though extra premium may result
therefrom) and without voiding the insurance coverage in force between the
insurer and the insured party. On reasonable request, each party shall be
entitled to have duplicates or certificates of policies containing such
provisions. Each party hereby waives all rights of recovery against the other
for loss or injury against which the waiving party is protected by insurance
containing said provisions, reserving, however, any rights with respect to any
excess of loss or injury over the amount recovered by such insurance.

SECTION 7Landlord's Covenants

Section 7.1.   
Quiet Enjoyment.  Tenant, on paying the rent and performing its
obligations hereunder, shall peacefully and quietly have, hold and enjoy the
Premises throughout the Term without any manner of hindrance or molestation from
Landlord or anyone claiming under Landlord, subject, however, to all the terms
and provisions hereof.

Section 7.2.   
Maintenance and Repair.  Subject to the provisions of Section 9,
Landlord shall maintain the roof, walls, subfloors, structural supports,
foundation and exterior of the Building and all standard common plumbing,
electrical, mechanical, heating, ventilating and air conditioning systems
installed by Landlord (but excluding (i) all special systems installed by Tenant
or by Landlord at Tenant's request, (ii) the fire suppression, life safety and
HVAC systems servicing the computer room located in the Third Floor Premises and
(iii) the kitchen equipment, sink and showers located in the First Floor
Premises and (iv) repairs or replacement occasioned by any act or negligence of
Tenant, its agents, customers or employees, all of which Tenant shall be solely
responsible for) in good order, repair and condition and shall maintain and
clean the interior common areas in the Building in accordance with the
specifications attached hereto as Exhibit D. Landlord shall have thirty (30)
days after notice from Tenant to perform any necessary maintenance or repairs
provided, however, that if such maintenance or repairs cannot be

15

---

completed within thirty (30) days, Landlord shall use reasonable efforts to
commence the maintenance or repair within such thirty (30) day period.

Section 7.3.   
Exterior Common Areas and Facilities.  Landlord shall maintain all
lawns and planted areas within the Lot and clean and maintain and provide snow
plowing for all parking areas, walks and driveways on the Lot, subject to the
provisions of Section 9.

Section 7.4.   
Heating and Air Conditioning.  From 8:00 a.m. to 6:00 p.m. Monday
through Friday and from 8:00 a.m. to l:00 p.m. on Saturdays (in all cases,
holidays excluded), Landlord shall furnish heating and cooling as normal
seasonal variations may require to provide reasonably comfortable space under
normal business operations and an occupancy of not more than one person per 200
square feet of usable floor area in order to provide temperatures reasonably
similar to other similar buildings in the general Waltham, Massachusetts
vicinity. Should Tenant require air conditioning or heating outside the hours
and days herein specified, Landlord shall furnish such service, and Tenant shall
pay to Landlord such charges therefor as Landlord may from time to time specify.
Landlord's charge for air conditioning or heating beyond such hours is
currently $40.00 per additional hour (or portion thereof). Tenant agrees to
cooperate with Landlord and to abide by all Building regulations which Landlord
may, from time to time, reasonably prescribe for the proper functioning and
protection of any heating, ventilating and air conditioning systems and in order
to maximize the effect thereof. Notwithstanding anything to the contrary set
forth in this Section 7.4 or otherwise in this Lease, Landlord may institute
such reasonable policies, programs and measures as may be necessary, required or
expedient for the conservation or preservation of energy or energy services, or
as may be necessary or required to comply with applicable codes, rules,
regulations and standards.

Section 7.5.   
Electricity.  Landlord, in its sole discretion, will either (a)
furnish electricity to the Premises sufficient to operate normal lighting and
business machines approved by Landlord (exclusive, however, of Tenant's
electrical needs for computers and similar equipment having special power or
environmental requirements and in no event shall Landlord be obligated to
furnish electricity to supply a requirement in excess of 3.0 watts per square
foot of usable area of the Premises), charging for such service, in addition to
Tenant's obligations to pay Operating Cost Escalation under Section 5.1, the
Tenant's Estimated Electrical Charge (which may be increased at any time during
the Term if the actual electricity cost for the Premises, as reasonably
determined by Landlord, is greater than the Tenant's Estimated Electrical
Charge), to be paid by Tenant as Additional Rent in equal monthly installments
on the same day in each month that rental payments are due and payable
hereunder, or (b) elect, at any time during the term, to cause electricity
furnished to the Premises to be separately metered, in which event all charges
for electricity consumed on the Premises will be billed directly to, and paid
by, Tenant, and Tenant thereafter will not be required to pay Tenant's Estimated
Electrical Charge. The cost of any such electric meter and the cost of
installation, repair and replacement thereof shall be borne by Landlord but
shall be recoverable through inclusion in Landlord's Operating Costs.

16

---

Whether or not Landlord is
furnishing electricity to Tenant, if Tenant shall require electricity in excess
of the quantity to be furnished under the preceding paragraph, Tenant shall upon
demand reimburse Landlord for the cost of such excess electricity. If (a) in
Landlord's judgment, Landlord's facilities are inadequate for such excess
requirements, or (b) such excess use shall result in an additional burden on the
Building's or office park's utility systems or additional cost on account
thereof, as the case may be, Tenant shall upon demand reimburse Landlord for all
additional costs related thereto.

Landlord shall furnish and install
the bulbs required within the Premises as of the Term Commencement Date, and
thereafter Landlord, at Tenant's sole cost and expense, shall replace and
install all ballasts, lamps and bulbs (including, but not limited to,
incandescent and flourescent) used in the Premises. All such replacements shall
be of a type, color and size as shall be designated by Landlord.

Landlord shall not in any way be
liable or responsible to Tenant for any loss, damage or expense which Tenant may
sustain or incur if the quantity, character, or supply of electricity is changed
or is no longer available or suitable for Tenant's requirements.

Section 7.6.   
Cleaning.  Landlord shall cause the Premises, at Landlord's
expense (but recoverable through inclusion in Landlord's Operating Costs), to
be cleaned substantially as set forth in the Cleaning Specifications attached as
Exhibit D - Cleaning Specifications.

Section 7.7.   
Interruptions.  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 power losses or shortages or from the necessity of
Landlord's entering the Premises for any of the purposes authorized by this
Lease or for repairing the Premises or any portion of the Building or Lot. In
case Landlord is prevented or delayed from making any repairs, alterations or
improvements, or furnishing any service or performing any other obligation to be
performed on Landlord's part, by reason of any cause, Landlord shall not be
liable to Tenant therefor, nor shall Tenant be entitled to any abatement or
reduction of rent by reason thereof, nor shall the same give rise to any claim
by Tenant that such failure constitutes actual or constructive, total or
partial, eviction from the Premises; provided, however, that if same is due to
the gross negligence or willful misconduct of Landlord, or its agents,
employees, contractors or invitees and Tenant's use of the premises is
materially adversely affected by the interruption in an essential utility
service for more than a 30 day consecutive period, Tenant shall be entitled, as
its sole and exclusive remedy, to an equitable abatement of rent for each day
after such 30 day period that such interruption continues.

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. 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.

17

---

Landlord also reserves the right
to institute such reasonable policies, programs and measures as may be
necessary, required or expedient for the conservation or preservation of energy
or energy services or as may be necessary or required to comply with applicable
codes, rules, regulations or standards. In so doing, Landlord shall make
reasonable efforts to avoid unnecessary inconvenience to Tenant by reason
thereof.

Section 7.8   
Tenant's Access to Building.  During normal Building hours, access
to the Premises shall be freely available, subject to interruption due to causes
beyond Landlord's reasonable controls and reasonable control and subject to
reasonable security restrictions. During other periods, Tenant shall have access
to the Premises through use of an entry door card access system, but such access
shall always be subject to reasonable rules and regulations from time to time
established for the Building by Landlord (and shall be subject to interruption
due to causes beyond Landlord's reasonable control). Tenant acknowledges that
Tenant is responsible for providing security to the Premises following
Tenant's entry onto the Premises for any reason and for its own personnel
whenever located therein. Subject to the foregoing, Landlord shall, at all
times, retain the right to control and prevent such access by all persons whose
presence, in the sole discretion of Landlord, shall be prejudicial to the
safety, protection, character, reputation and interests of the Building and its
tenants or occupants. Landlord shall in no case be liable for damages resulting
from any error with regard to the admission or exclusion of any person to or
from the Building.

SECTION 8Tenant's Covenants

Section 8.1.   
Use.  Tenant shall use the Premises only for the Permitted Uses and
shall from time to time procure all licenses and permits necessary therefor at
Tenant's sole expense.

Section 8.2.   
Repair and Maintenance.  Except as otherwise provided in Sections 7
and 9, Tenant shall keep the Premises (but not the systems serving the Premises
except Tenant shall be responsible to repair and maintain in good order and
condition and replace as necessary (i) all special systems installed by Tenant
or by Landlord at Tenant's request, (ii) the fire suppression, life safety and
HVAC systems servicing the computer room located in the Third Floor Premises and
(iii) the kitchen equipment, sink and showers located in the First Floor
Premises) in good order, condition and repair and in at least as good order,
condition and repair as they are in on the Commencement Date or may be put in
during the term, reasonable use and wear and damage due to fire or other insured
casualty or eminent domain only excepted; and to make as and when needed as a
result of misuse by, or neglect or improper conduct of, Tenant or Tenant's
servants, employees, agents, invitees or licensees or otherwise, all repairs in
and about the Premises necessary to preserve them in such repair, order and
condition, which repairs shall be in quality and class equal to the original
work . Tenant shall make all repairs and replacements and do all other work
necessary for the foregoing purposes whether the same may be ordinary or
extraordinary,

18

---

foreseen or unforeseen. Tenant shall keep in a safe, secure and sanitary
condition all trash and rubbish temporarily stored at the Premises.

Section 8.3.   
Compliance with Law and Insurance Requirements. Tenant shall make all
repairs, alterations, additions or replacements to the Premises required by any
law or ordinance or any order or regulation of any public authority arising from
Tenant's use of the Premises or alterations, improvements or additions to the
Premises performed by Tenant and shall keep the Premises equipped with all
safety appliances so required. Tenant shall not dump, flush, or in any way
introduce any hazardous substances or any other toxic substances into the
septic, sewage or other waste disposal system serving the Premises, or generate,
store or dispose of hazardous substances in or on the Premises or dispose of
hazardous substances from the Premises to any other location without the prior
written consent of Landlord and then only in compliance with the Resource
Conservation and Recovery Act of 1976, as amended, 42 U.S.C. §6901 et seq., the
Massachusetts Hazardous Waste Management Act, M.G.L. c.21C, as amended, the
Massachusetts Oil and Hazardous Material Release Prevention and Response Act,
M.G.L. c. 21E, as amended, and all other applicable codes, regulations,
ordinances and laws. Tenant shall notify Landlord of any incident which would
require the filing of a notice under Chapter 232 of the Acts of 1982 and shall
comply with the orders and regulations of all governmental authorities with
respect to zoning, building, fire, health and other codes, regulations,
ordinances or laws applicable to the Premises. "Hazardous substances"
as used in this Section shall mean "hazardous substances" as defined
in the Comprehensive Environmental Response Compensation and Liability Act of
1980, as amended, 42 U.S.C. §9601 and regulations adopted pursuant to said Act.

Landlord may, if it so elects,
make any of the repairs, alterations, additions or replacements referred to in
this Section which affect the Building structure or the Building systems, and
Tenant shall reimburse Landlord for the cost thereof on demand.

Tenant will provide Landlord, from
time to time upon Landlord's request, with all records and information regarding
any hazardous substance maintained on the Premises by Tenant.

Landlord shall have the right, at
Tenant's expense, to make such inspections as Landlord shall reasonably elect
from time to time to determine if Tenant is complying with this Section.

Tenant shall comply promptly with
the recommendations of any insurer, foreseen or unforeseen, ordinary as well as
extraordinary, which may be applicable to the Premises, by reason of Tenant's
use thereof. In no event shall any activity be conducted by Tenant on the
Premises which may give rise to any cancellation of any insurance policy or make
any insurance unobtainable.

Section 8.4.   
Tenant's Work.  Tenant shall not make any installations,
alterations, additions or improvements in or to the Premises, including, without
limitation, any apertures in the walls, partitions, ceilings or floors, without
on each occasion obtaining the

19

---

prior written consent of Landlord; provided, however, that (i) Landlord shall
not unreasonably withhold or delay its consent to any installations,
alterations, additions or improvements which do not affect the Building systems
or the structure of the Building or its components; and (ii) Landlord's consent
shall not be required for any work that does not affect the Building systems or
the structure of the Building or its components so long as such work shall not
cost in excess of $10,000 to complete. Any such work so consented to by Landlord
shall be performed only in accordance with plans and specifications therefor
approved by Landlord. Tenant shall procure at Tenant's sole expense all
necessary permits and licenses before undertaking any work on the Premises and
shall perform all such work in a good and workmanlike manner employing materials
of good quality and so as to conform with all applicable zoning, building, fire,
health and other codes, regulations, ordinances and laws and with all applicable
insurance requirements. If requested by Landlord, Tenant shall furnish to
Landlord prior to the commencement of any such work a bond or other security
acceptable to Landlord assuring that any work by Tenant will be completed in
accordance with the approved plans and specifications. Tenant shall keep the
Premises at all times free of liens for labor and materials. Tenant shall employ
for such work only contractors approved by Landlord and shall require all
contractors employed by Tenant to carry worker's compensation insurance in
accordance with statutory requirements and commercial general liability
insurance covering such contractors, and naming Landlord, Landlord's property
manager and Tenant as additional insureds, on or about the Premises in amounts
at least equal to the limits set forth in Section 1 and to submit certificates
evidencing such coverage to Landlord prior to the commencement of such work.
Tenant shall save Landlord harmless and indemnified from all injury, loss,
claims or damage to any person or property occasioned by or growing out of such
work. Landlord may inspect the work of Tenant at reasonable times and give
notice of observed defects.

Section 8.5.   
Indemnity.  Tenant shall defend, with counsel approved by Landlord,
all actions against Landlord, any partner, trustee, stockholder, officer,
director, employee, agent or beneficiary of Landlord, holders of mortgages
secured by the Building and any other party having an interest in the Premises
("Indemnified Parties") with respect to, and shall pay, protect,
indemnify and save harmless, to the extent permitted by law, all Indemnified
Parties from and against, any and all liabilities, losses, damages, costs,
expenses (including reasonable attorneys' fees and expenses), causes of action,
suits, claims, demands or judgments of any nature arising from: (a) injury to or
death of any person, or damage to or loss of property, occurring in or about the
Premises or connected with the use, condition or occupancy of any thereof unless
caused by the negligence of Landlord or its servants or agents; (b) violation of
this Lease by Tenant; or (c) any act, fault, omission, or other misconduct of
Tenant or its agents, contractors, licensees, sublessees or invitees.

Section 8.6.   
Landlord's Access.  (a) Tenant shall permit Landlord, Landlord's
agents and contractors, and appropriate public utility service providers to
erect, use and maintain, repair and replace concealed ducts, pipes, lines and
conduits in and through the Premises provided such use does not cause the usable
area of the Premises to be reduced beyond a de minimis amount. Landlord
shall promptly repair any damage to the Premises

20

---

or Tenant's personal property caused by any work performed pursuant to this
Section 8.6(a).

(b)    Landlord,
any ground lessor or mortgagee and any other party designated by Landlord and
their respective agents shall have the right to enter the Premises at all
reasonable times, upon reasonable notice (which notice may be oral) except in
the case of emergency (when no notice shall be required), (I) to examine the
Premises during the Term, (II) to show the Premises during the Term to
prospective purchasers, mortgagees or ground lessors of the Building and their
respective agents and representatives or others, and during the last 12 months
of the Term (unless Tenant exercises its option to extend pursuant to Section
2.3, in which event the last twelve months of the Extension Term) to prospective
tenants, and (III) during the Term to make such repairs, alterations or
additions to the Premises or the Building (i) as Landlord may deem necessary or
appropriate, (ii) which Landlord may elect to perform following Tenant's
failure to perform, or (iii) to comply with any legal requirements, and Landlord
shall be allowed to take all materials into the Premises that may be required
for the performance of such work without the same constituting an actual or
constructive eviction of Tenant in whole or in part and without any abatement of
rent.

(c)    All parts
(except surfaces facing the interior of the Premises) of all walls, windows and
doors bounding the Premises (including exterior Building walls, exterior core
corridor walls, and doors and entrances other than doors and entrances solely
connecting areas within the Premises), all balconies, terraces and roofs
adjacent to the Premises, all space in or adjacent to the Premises used for
shafts, stacks, stairways, mail chutes, conduits and other mechanical
facilities, Building systems and Building facilities are not part of the
Premises, and Landlord shall have the use thereof and access thereto through the
Premises for the purposes of Building operation, maintenance, alteration,
improvement and repair.

(d)    If, during
the last twelve (12) months of the Term, Tenant removes all or substantially all
of Tenant's property from the Premises and vacates the same, Landlord may,
upon prior notice to Tenant (which notice may be oral), renovate and/or
redecorate the Premises, without abatement of any rent or incurring any
liability to Tenant. Such acts shall not be deemed an actual or constructive
eviction and shall have no effect upon this Lease.

Section 8.7.   
Alterations to Building.  Landlord shall have the right at any time
or from time to time, in its sole discretion, to (a), upon at least ninety (90)
days prior notice to Tenant, change the name, number or designation by which the
Building is commonly known, and (b) alter the Building to change the arrangement
or location of entrances or passageways, doors and doorways, and corridors,
elevators, stairs, toilets, or other public parts of the Building without any
such acts constituting an actual or constructive eviction and without incurring
any liability to Tenant, so long as such changes do not deprive Tenant of
commercially reasonable access to the Premises.

21

---

Section 8.8.   
Personal Property at Tenant's Risk.  All furnishings, fixtures,
equipment, effects and property of every kind of Tenant and of all persons
claiming by, through or under Tenant which may be on the Premises, 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 shall be charged to or to be borne by Landlord,
except that Landlord shall not be indemnified or held harmless or exonerated
from any liability to Tenant for any injury, loss, damage or liability caused by
Landlord's negligence or willful misconduct except to the extent, in the case
of Landlord's negligence, the loss is covered by Tenant's insurance. Tenant
shall be solely responsible to insure Tenant's personal property.

Section 8.9.   
Payment of Landlord's Cost of Enforcement.  Tenant shall pay, on
demand, Landlord's expenses, including reasonable attorney's fees, incurred in
enforcing any obligation of Tenant under this Lease or in curing any default by
Tenant under this Lease as provided in Section 10.4.

Section 8.10.   
Yield Up.  At the expiration of the term or earlier termination of
this Lease, Tenant shall surrender all keys to the Premises, remove all of its
trade fixtures and personal property in the Premises, remove such installations
and improvements made by Tenant as Landlord may request and all Tenant's signs
wherever located, repair all damage caused by such removal and yield up the
Premises (including all installations and improvements made by Tenant which
Landlord shall not request Tenant to remove) broom-clean and in the same good
order and repair in which Tenant is obliged to keep and maintain the Premises
under this Lease. Any property not so removed shall be deemed abandoned and may
be removed and disposed of by Landlord in such manner as Landlord shall
determine, and Tenant shall pay Landlord the entire cost and expense incurred by
it in effecting such removal and disposition and in making any incidental
repairs and replacements to the Premises and for use and occupancy during the
period after the expiration of the term and prior to Tenant's performance of its
obligations under this Section 8.10.

Section 8.11.   
Estoppel Certificate.  Upon not less than ten (10) business days'
prior written request by Landlord or Tenant, the non-requesting party shall
execute, acknowledge and deliver to the requesting party a statement in writing
certifying that this Lease is unmodified and in full force and effect and that,
except as stated therein, the non-requesting party has no knowledge of any
defenses, offsets or counterclaims against the non-requesting party's
obligations under the Lease, including any payments due thereunder, (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
or counterclaims, setting them forth in reasonable detail), the dates to which
the Annual Rent and Additional Rent and other charges have been paid and a
statement that the requesting party is not in default hereunder (or if in
default, the nature of such default, in reasonable detail). Any such statement
delivered pursuant to this Section 8.11 may be relied upon by any prospective
purchaser or mortgagee of the Building or any permitted sublessee or assignee of
this Lease.

22

---

Section 8.12.   
Landlord's Expenses Re Consents.  Tenant shall reimburse Landlord
promptly on demand for all reasonable legal and other expenses incurred by
Landlord in connection with all requests by Tenant for consent or approval
hereunder.

Section 8.13.   Rules
and Regulations.  Tenant shallcomply with the Rules and Regulations
attached hereto as Exhibit E and such other reasonable Rules and
Regulations as may be adopted from time to time by Landlord to provide for the
beneficial operation of the Lot and Building; provided, however, that Landlord
shall not discriminate against Tenant in the enforcement of such Rules and
Regulations.

Section 8.14.   Holding
Over.  Tenant shall vacate the Premises immediately upon the expiration
or sooner termination of this Lease. If Tenant retains possession of the
Premises or any part thereof after the termination of the term without
Landlord's express consent, Tenant shall pay Landlord rent at double the monthly
rate specified in Section 1 (most recently in effect just prior to such
termination) for the time Tenant thus remains in possession and, in addition
thereto, shall pay Landlord for all damages, consequential as well as direct,
sustained by reason of Tenant's retention of possession. The provisions of this
Section do not exclude Landlord's rights of re-entry or any other right
hereunder, including without limitation, the right to remove Tenant through
summary proceedings for holding over beyond the expiration of the term of this
Lease.

Section 8.15.   Assignment
and Subletting . Tenant shall not assign, transfer, mortgage or pledge
this Lease or grant a security interest in Tenant's rights hereunder or sublease
(which term shall be deemed to include the granting of concessions and licenses
and the like) all or any part of the Premises or suffer or permit this Lease or
the leasehold estate hereby created or any other rights arising under this Lease
to be assigned, transferred or encumbered, in whole or in part, whether
voluntarily, involuntarily or by operation of law, or permit the occupancy of
the Premises by anyone other than Tenant; provided, however, that (a) Tenant
shall have the right to sublease the Premises or assign this Lease to any entity
that controls, is controlled by or is under common control with Tenant without
Landlord's prior consent so long as Tenant provides Landlord with prior
written notice thereof and so long as such entity, in the case of an assignment,
assumes all of the Tenant's obligations hereunder by a written instrument
approved by Landlord and so long as such entity shall have a net worth
immediately after such assignment at least equal to that of Tenant as of the
date of this Lease; and (b) Tenant shall have the right, subject to the below
provisions of this Section 8.15, to sublet all or portions of the Premises to
third parties upon obtaining Landlord's prior written consent, which consent
shall not be unreasonably withheld or delayed. In connection with any request by
Tenant for such consent to an assignment or subletting, Tenant shall submit to
Landlord in writing (i) the name of the proposed assignee or subtenant, (ii)
such information as to its reputation, financial responsibility and standing as
Landlord may reasonably require, including, without limitation, business
references and references from prior landlords, and (iii) all of the terms and
provisions upon which the proposed assignment or subletting is to be made. As
additional rent, Tenant shall reimburse Landlord promptly for reasonable legal
and other expenses incurred by Landlord in connection with any request by Tenant
for consent

23

---

to any assignment or subletting.  Any sale or transfer after the date
hereof, whether to one or more persons or entities and whether at one or more
different times, and whether voluntarily, involuntarily, by operation of law or
otherwise (including, without limitation, upon a merger, consolidation,
reorganization or other such transaction), of (a) all or substantially all of
Tenant's assets or (b) of a total of fifty percent (50%) or more of the shares
of capital stock of any corporation which is then the legal tenant under this
lease or the legal subtenant under any permitted sublease hereunder shall be
deemed an assignment within the meaning of this Section 8.15, except that so
long as (i) BroadVision shall have a net worth at the time of the proposed sale
or transfer of at least $150,000,000 (as evidenced by financial statements and
other written information reasonably requested by Landlord) and (ii) Tenant
shall not be in default under this Lease beyond the expiration of applicable
notice and cure periods at the time of such sale or transfer (including, without
limitation upon a merger or other such transaction), Landlord shall consent to
the sale or transfer to BroadVision of all or substantially all of Interleaf,
Inc.'s assets or a transfer to BroadVision of 50% or more of Interleaf, Inc.'s
capital stock.

Notwithstanding whether or not
Landlord consents to any subletting or assignment:  (i) in no event shall
Tenant sublet to more than three subtenants at any one time; and (ii) in no
event shall Tenant enter into negotiations to assign this Lease or sublet, or
offer to assign or sublet, or sublet or assign to any of the other tenants of
the Building or to any party with whom Landlord is then negotiating with respect
to other space in the Building.

Notwithstanding anything to the
contrary contained in this Section 8.15, provided that (i) Tenant shall not be
in default under this Lease beyond the expiration of applicable notice and cure
periods at the time of the "BroadVision Assignment;" (ii) BroadVision, Inc.,
a Delaware corporation ("BroadVision") shall have a net worth at the time of
the proposed assignment by Interleaf, Inc. of this Lease of at least
$150,000,000.00 (as evidenced by financial statements and other written
information reasonably requested by Landlord); (iii) BroadVision enters into a
written assignment and assumption agreement in a form satisfactory to Landlord
with Interleaf, Inc. and Landlord whereby BroadVision accepts the assignment of
this Lease by Interleaf, Inc. and agrees to assume all of the obligations of
Interleaf, Inc. under this Lease from the initial date of this Lease and
continuing through the expiration of the term of the Lease, including any
Extension Term); and (iv) BroadVision provides the Landlord with legal existing
certificates and corporate resolutions evidencing the entity status of
BroadVision as of the date of the assignment and the authority of BroadVision to
enter into the assignment and assumption of this Lease, Landlord shall consent
to an assignment of this Lease by Interleaf, Inc. to BroadVision (the "BroadVision Assignment").

Any attempted assignment,
transfer, mortgage, pledge, grant of security interest, sublease or other
encumbrance, except with the prior consent thereto by Landlord, shall be void.
No assignment, transfer, mortgage, grant of security interest, sublease or other
encumbrance, whether or not consented to (and whether or not any consent shall
have been required hereunder), and no indulgence granted by Landlord to any
assignee or sublessee, shall in any way impair the continuing primary liability
(which after an assignment shall be joint and several with the assignee) of
Tenant hereunder, and no consent in a particular

24

---

instance shall be deemed to be a waiver of the obligation to obtain
Landlord's consent in any other case.

If for any assignment or sublease
Tenant shall receive rent or other consideration, either initially or over the
term of the assignment or sublease, in excess of the rent called for hereunder
(or in the case of the sublease of part, in excess of such rent allocable to the
part) after appropriate adjustments to assure that all other payments called for
hereunder are taken into account and after subtracting from such excess amount
the following expenses incurred by Tenant as a result of the assignment or
subletting of such space, all amortized ratably over the term of the sublease or
assignment: (i) any leasehold improvements made to the Premises on account
thereof; (ii) any commercially reasonable brokerage commissions paid therefor;
and (iii) any commercially reasonable attorneys' fees paid by Tenant therefor,
Tenant shall pay to Landlord, as Additional Rent, 50% of such excess of such
payment of rent or other consideration received by Tenant, promptly after its
receipt.

Section 8.16.   
Overloading and Nuisance.  Tenant shall not injure, overload, deface
or otherwise harm the Premises, commit any nuisance, permit the emission of any
objectionable noise, vibration or odor, make, allow or suffer any waste or make
any use of the Premises which is improper, offensive or contrary to any law or
ordinance or which will invalidate any of Landlord's insurance.

SECTION 9
Casualty or Taking

Section 9.1.   
Termination.  In the event that 35% or more of the Building shall be
destroyed or damaged by fire or casualty (a "Casualty") then this lease may
be terminated by Landlord by notice given to Tenant within sixty (60) days after
the Casualty.

In the event that the
Premises or a substantial portion thereof (or all reasonable means of access to
the Premises) shall be destroyed or damaged by a Casualty and if Landlord's
architect, engineer or contractor shall determine that it will require in excess
of 210 days from the date of Landlord's receipt of insurance proceeds to
restore the Premises (or the reasonable means of access thereto), this Lease may
be terminated by either Landlord or Tenant by notice to the other given within
sixty (60) days after the Casualty. In the event of a termination of this Lease
under this Section 9.1, Annual Rent and Additional Rent shall be abated,
according to the nature and extent of the damages to the Premises, from the date
of the Casualty until such termination, provided, however, that in no event
shall Tenant be entitled to any abatement of rent on account of a Casualty if
such casualty was caused by the negligence or willful misconduct of Tenant or
Tenant's agents, employees or contractors.

In the event that
greater than twenty (20) percent of the Building or greater than ten (10)
percent of the Lot shall be taken by any public authority or for any public use
or destroyed by the action of any public authority (a "Taking") then
this Lease may be terminated by Landlord effective on the effective date of the
Taking.

25

---

In the case of a Taking of a
substantial portion of the Premises or of all reasonable means of access
thereto, Landlord or Tenant shall have the right to terminate this Lease
effective as of the date of such Taking. In the case of a Taking under this
Section 9.1 that entitles either party to elect to terminate this Lease, such
election, which may be made notwithstanding the fact that Landlord's or
Tenant's entire interest may have been divested, shall be made by the giving
of notice by Landlord or Tenant to the other within thirty (30) days after
Landlord or Tenant, as the case may be, shall receive notice of the Taking.

In the case of a Taking of a
substantial portion of the Premises or of all reasonable means of access
thereto, Landlord or Tenant shall have the right to terminate this Lease
effective as of the date of such Taking. In the case of a Taking under this
Section 9.1 that entitles either party to elect to terminate this Lease, such
election, which may be made notwithstanding the fact that Landlord's or
Tenant's entire interest may have been divested, shall be made by the giving
of notice by Landlord or Tenant to the other within thirty (30) days after
Landlord or Tenant, as the case may be, shall receive notice of the Taking.

Section 9.2.   
Restoration.  In the event of a Taking or a Casualty, unless
Landlord or Tenant shall exercise an election to terminate provided in Section
9.1, this Lease shall continue in force and a just proportion of the Annual Rent
and other charges hereunder, according to the nature and extent of the damages
sustained by the Premises, but not in excess of an equitable portion of the net
proceeds of insurance recovered by Landlord under the rental insurance carried
pursuant to Section 6.2, shall be abated until the Premises, or what may remain
thereof, shall be put by Landlord in proper condition for use subject to zoning
and building laws or ordinances then in existence, which, unless Landlord or
Tenant has exercised its option to terminate pursuant to Section 9.1, Landlord
covenants to do with reasonable diligence at Landlord's expense. Landlord's
obligations with respect to restoration shall not require Landlord to expend
more than the net proceeds of insurance recovered or damages awarded for such
Casualty or Taking and made available for restoration by Landlord's mortgagees.
"Net proceeds of insurance recovered or damages awarded" refers to the
gross amount of such insurance or damages less the reasonable expenses of
Landlord in connection with the collection of the same, including without
limitation, fees and expenses for legal and appraisal services.

Section 9.3.   
Award.  Irrespective of the form in which recovery may be had by
law, all rights to damages or compensation shall belong to Landlord in all
cases. Tenant hereby grants to Landlord all of Tenant's rights to such damages
and compensation and covenants to deliver such further assignments thereof as
Landlord may from time to time request.

26

---

SECTION 10
Default

Section 10.1.   
Events of Default.  If

(a)    Tenant shall
default in the performance of any of its obligations to pay the Annual Rent,
Additional Rent or any other sum payable hereunder and if such default shall
continue for five (5) days after notice to Tenant; provided, however, that
Landlord shall not be obligated to provide such notice of non-payment to Tenant
if within the then prior twelve calendar month period, Landlord has provided two
such notices of non-payment to Tenant;

(c)    if any
assignment for the benefit of creditors shall be made by Tenant;

(e)    if a lien or
other involuntary encumbrance is filed against Tenant's leasehold interest, and
is not discharged within thirty (30) days thereafter;

(g)    if an
involuntary petition under any of the provisions of said Bankruptcy Code is
filed against Tenant and such involuntary petition is not dismissed within sixty
(60) days thereafter, then, and in any of such cases, Landlord and the agents
and servants of Landlord lawfully may, in addition to and not in derogation of
any remedies for any preceding breach of covenant, immediately or at any time
thereafter and without demand or notice and with or without process of law
(forcibly, if necessary) enter into and upon the Premises or any part thereof in
the name of the whole, or mail a notice of termination addressed to Tenant, and
repossess the same as of Landlord's former estate and expel Tenant and those
claiming through or under Tenant and remove its and their effects without being
deemed guilty of any manner of trespass and without prejudice to any remedies
which might otherwise be used for arrears of rent or prior breach of covenant,
and upon such entry or mailing as aforesaid this Lease shall terminate, Tenant
hereby waiving all statutory rights (including, without limitation, rights of
redemption, if any) to the extent such rights may be lawfully waived. Landlord,
without notice to Tenant, may

27

---

store Tenant's effects, and those of any person claiming through or under
Tenant at the expense and risk of Tenant, and, if Landlord so elects, may sell
such effects at public auction or private sale and apply the net proceeds to the
payment of all sums due to Landlord from Tenant, if any, and pay over the
balance, if any, to Tenant.

Section 10.2.   
Remedies.  In the event that this Lease is terminated under any of
the provisions contained in Section 10.1, Tenant shall pay forthwith to
Landlord, as compensation, the excess of the total rent reserved for the residue
of the Term over the fair market rental value of the Premises for the residue of
the term; provided that such excess amount shall be computed by discounting such
excess amount at the then applicable discount rate of the Federal Reserve Bank
located in Boston, Massachusetts. In calculating the rent reserved there shall
be included, in addition to the Annual Rent and Additional Rent, the value of
all other considerations agreed to be paid or performed by Tenant during the
residue. As additional and cumulative obligations after any such termination,
Tenant shall also pay punctually to Landlord all the sums and shall 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 pursuant to
the preceding sentence, Tenant shall be credited with any amount paid to
Landlord pursuant to the first sentence of this Section 10.2 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, reasonable
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 hereof and may grant such concessions and
free rent as Landlord in its reasonable judgment considers advisable or
necessary to relet the same and (ii) make such alterations, repairs and
decorations in the Premises as Landlord in its reasonable 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.

Section 10.3.   
Remedies Cumulative.  Except as otherwise expressly provided herein,
any and all rights and remedies which Landlord may have under this Lease and at
law and equity shall be cumulative and shall not be deemed inconsistent with
each other, and any two or more of all such rights and remedies may be exercised
at the same time to the greatest extent permitted by law.

Section 10.4.   
Landlord's Right to Cure Defaults.  At any time following twenty
(20) days' prior notice to Tenant (except in cases of emergency when no notice
shall be required), Landlord may (but shall not be obligated to) cure any
default by Tenant under this Lease, and whenever Landlord so elects, all costs
and expenses incurred by Landlord, including reasonable attorneys' fees, in
curing a default shall be paid by Tenant to Landlord as Additional Rent on
demand, together with interest thereon at the rate

28

---

provided in Section 10.7 from the date of payment by Landlord to the date of
payment by Tenant.

Section 10.5.   
Effect of Waivers of Default.  Any consent or permission by Landlord
to any act or omission which otherwise would be a breach of any covenant or
condition herein, or any waiver by Landlord of the breach of any covenant or
condition herein, shall not in any way be held or construed (unless expressly so
declared) to operate so as to impair the continuing obligation of any covenant
or condition herein, or otherwise operate to permit the same or similar acts or
omissions except as to the specific instance. The failure of Landlord to seek
redress for violation of, or to insist upon the strict performance of, any
covenant or condition of this Lease 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. The
receipt by Landlord of rent with knowledge of the breach of any covenant of this
Lease shall not be deemed to have been a waiver of such breach by Landlord or of
any of Landlord's remedies on account thereof, including its right of
termination for such default.

Section 10.6.   
No Accord and Satisfaction.  No acceptance by Landlord of a lesser
sum than the Annual Rent, Additional Rent or any other sum then due shall be
deemed to be other than on account of the earliest installment of such rent or
charge due, unless Landlord elects by notice to Tenant to credit such sum
against the most recent installment due. Any endorsement or statement on any
check or any letter accompanying any check or payment as rent or other charge
shall not be deemed an accord and satisfaction, and Landlord may accept such
check or payment without prejudice to Landlord's right to recover the balance of
such installment or pursue any other remedy under this Lease or otherwise.

Section 10.7.   
Interest on Overdue Sums; Late Charge.  If Tenant fails to pay
Annual Rent, Additional Rent or other sums payable by Tenant to Landlord within
five (5) days after the due date thereof (i.e., the due date disregarding any
requirement of notice from Landlord or any period of grace allowed to Tenant),
the amount so unpaid shall bear interest at a variable rate (the
"Delinquency Rate") equal to four percent (4%) in excess of the prime
rate published in The Wall Street Journal from time to time in effect
commencing with the due date and continuing through the day on which payment of
such delinquent payment with interest thereon is paid. If such rate is in excess
of any maximum interest rate permissible under applicable law, the Delinquency
Rate shall be the maximum interest rate permissible under applicable law.

In addition to all of the rights
and remedies of Landlord set forth in this Lease, including the above paragraph,
if Tenant shall fail to pay any item of rental due hereunder (whether
denominated as Annual Rent, Additional rent or otherwise) within five (5) days
after the same shall have become due and payable (i.e., the due date
disregarding any requirement of notice from Landlord or any period of grace
allowed to Tenant), then and in such event Tenant shall also pay to Landlord a
late payment service charge (in order to partially defray Landlord's
administrative and other overhead expenses) equal to the greater of three
hundred (300) dollars or one percent (1%) of such unpaid sum. It being

29

---

understood that nothing herein shall be deemed to extend the due date for
payment of any sums required to be paid by Tenant hereunder or to relieve Tenant
of its obligation to pay such sums at the time or times required by this Lease.

SECTION 11
Mortgages

Section 11.1.   
Rights of Mortgage Holders.  No Annual Rent, Additional Rent or any
other charge shall be paid more than ten (10) days prior to the due date thereof
and payments made in violation of this provision shall (except to the extent
that such payments are actually received by a mortgagee in possession or in the
process of foreclosing its mortgage) be a nullity as against such mortgagee and
Tenant shall be liable for the amount of such payments to such mortgagee.

In the event of any
act or omission by Landlord which would give Tenant the right to terminate this
Lease or to claim a partial or total eviction, Tenant shall not exercise any
such right (a) until it shall have given notice, in the manner provided in
Section 12.1, of such act or omission to the holder of any mortgage encumbering
the Premises whose name and address shall have been furnished to Tenant in
writing, at the last address so furnished, and (b) until thirty (30) days shall
have elapsed following the giving of such notice or such reasonable period of
time thereafter as is necessary for remedying such act or omission, provided
that following the giving of such notice, Landlord or such holder shall, with
reasonable diligence, have commenced and continued to remedy such act or
omission or to cause the same to be rendered.

Section 11.2.   
Subordination and Attornment.  (a) This Lease is subject and
subordinate to all current or future mortgages and ground leases affecting the
Building and/or Lot, and, at the request of any mortgagee or ground lessor,
Tenant shall attorn to such mortgagee or ground lessor, its successors in
interest or any purchaser in a foreclosure sale, provided that the mortgagee or
ground lessor, as the case may be, agrees, by a written instrument in recordable
form and in the customary form of such mortgagee or ground lessor
("Nondisturbance Agreement") that, as long as Tenant shall not be in default
of the obligations on its part to be kept and performed under the terms of this
Lease, this Lease will not be affected and Tenant's possession hereunder will
not be disturbed by any default in, termination, and/or foreclosure of, such
mortgage or ground lease, as the case may be.

(b)   
If a ground lessor or mortgagee or any other person or entity shall succeed to
the rights of Landlord under this Lease, whether through possession or
foreclosure action or the delivery of a new lease or deed, or otherwise, then at
the request of the successor landlord, Tenant shall be deemed to have attorned
to and recognized such successor landlord as Landlord under this Lease. The
provisions of this Article are self-operative and require no further instruments
to give effect hereto; provided, however, that Tenant shall promptly execute and
deliver any instrument that such successor landlord may reasonably request (i)
evidencing such attornment, (ii) setting forth the terms and conditions of
Tenant's tenancy, and (iii) containing such other terms and conditions as may

30

---

be required by such mortgagee or ground lessor, provided that such successor
landlord is obligated to recognize Tenant pursuant to the provisions of a
Nondisturbance Agreement, as defined in Section 10.1(a). Upon such attornment
this Lease shall continue in full force and effect as a direct lease between
such successor landlord and Tenant upon all of the terms, conditions and
covenants set forth in this Lease except that such successor landlord shall not
be:

(i)    liable for
any act or omission of any prior landlord except for any continuing defaults
relating to the maintenance or repair of the Premises of which Tenant shall have
given such ground lessor or mortgagee prior written notice;

(ii)    subject to
any defense, claim, counterclaim, set-off or offsets which Tenant may have
against any prior landlord;

(iii)    bound by
any prepayment of more than one month's rent to any prior landlord;

(iv)    bound by
any obligation to make any payment to Tenant which was required to be made prior
to the time such successor landlord succeeded to Landlord's interest;

(v)    bound by any
obligation to perform any work or to make improvements to the Premises; or

(vi)    bound by
any modification, amendment or renewal of this Lease made without the successor
landlord's consent.

Section 11.3.   
Subordination of Mortgage.  Any mortgagee may elect that this Lease
shall have priority over the mortgage that it holds and, upon notification to
Tenant by such mortgagee, this Lease shall be deemed to have priority over such
Mortgage, regardless of the date of this Lease.

Section 11.4.   
Provisions.  The provisions of this Article shall (a) inure to the
benefit of Landlord, any future owner of the Building or the Lot, ground lessor
or mortgagee and (b) apply notwithstanding that, as a matter of law, this Lease
may terminate upon the termination of any such ground lease or mortgage.

SECTION 12
Miscellaneous Provisions

Section 12.1.   
Notices from One Party to the Other.  All notices required or
permitted hereunder shall be in writing and shall be sent by overnight delivery
via a nationally recognized overnight carrier that maintains delivery receipts
or shall be sent via in-hand delivery and shall be addressed, if to Tenant, at
the Address of Tenant or such other address as Tenant shall have last designated
by notice in writing to Landlord and, if to Landlord, at the Address of Landlord
or such other address as Landlord shall have last

31

---

designated by notice in writing to Tenant. Any notice shall be deemed duly
given when delivered or tendered for delivery at such address.

Section 12.2.   
Quiet Enjoyment.  Landlord agrees that upon Tenant's paying the rent
and performing and observing the terms, covenants, conditions and provisions on
its part to be performed and observed, Tenant shall and may peaceably and
quietly have, hold and enjoy the Premises during the term without any manner of
hindrance or molestation from Landlord or anyone claiming under Landlord,
subject, however, to the terms of this Lease.

Section 12.3.   
Lease Not to be Recorded; Notice of Lease.  Tenant agrees that it
will not record this Lease. If the Term of this Lease, including options,
exceeds seven years, Landlord and Tenant agree that, on the request of either,
they will enter and record a notice of lease in form reasonably acceptable to
Landlord.

Section 12.4.   
Bind and Inure; Limitation of Landlord's Liability.  The obligations
of this Lease shall run with the Lot, and this Lease shall be binding upon and
inure to the benefit of the parties hereto and their respective successors and
assigns. No owner of the Premises shall be liable under this Lease except for
breaches of Landlord's obligations occurring while owner of the Premises. The
obligations of Landlord shall be binding upon the assets of Landlord which
comprise the Premises but not upon other assets of Landlord. No individual
partner, trustee, stockholder, officer, director, employee or beneficiary of
Landlord shall be personally liable under this Lease and Tenant shall look
solely to Landlord's interest in the Premises in pursuit of its remedies upon an
event of default hereunder, and the general assets of Landlord and its partners,
trustees, stockholders, officers, employees or beneficiaries of Landlord shall
not be subject to levy, execution or other enforcement procedure for the
satisfaction of the remedies of Tenant.

Section 12.5.   
Acts of God.  In any case where either party hereto is required to
do any act (other than the payment of money), delays caused by or resulting from
acts of God, war, civil commotion, fire, flood or other casualty, labor
difficulties, shortages of labor, materials or equipment, government
regulations, unusually severe weather, or other causes beyond such party's
reasonable control shall not be counted in determining the time during which
work shall be completed, whether such time be designated by a fixed date, a
fixed time or a "reasonable time", and such time shall be deemed to be
extended by the period of such delay.

Section 12.6.   
Landlord's Default.  Landlord shall not be deemed to be in default
in the performance of any of its obligations hereunder unless it shall fail to
perform such obligations within thirty (30) days after notice from Tenant to
Landlord specifying such default or, if such default cannot be cured within such
30 day period, Landlord has not commenced diligently to correct the default so
specified within 30 days or has not thereafter diligently pursued such
correction to completion. Tenant shall have no right, for any default by
Landlord, to offset or counterclaim against any rent due hereunder.

32

---

Section 12.7.   
Brokerage.  Tenant warrants and represents to Landlord that it has
had no dealings with any broker or agent in connection with this Lease other
than the Brokers set forth in Section 1 and covenants to defend with counsel
approved by Landlord, hold harmless and indemnify Landlord from and against any
and all cost, expense or liability for any compensation, commissions and charges
claimed by any broker or agent other than the Broker set forth in Section 1.

Section 12.8.   
Miscellaneous.  This Lease shall be governed by and construed in
accordance with the laws of the Commonwealth of Massachusetts. There are no
prior oral or written agreements between Landlord and Tenant affecting this
Lease.

Section 12.9.   
Security Deposit.  Tenant shall deposit the Security Deposit with
Landlord upon the execution of this Lease in cash as security for the faithful
performance and observance by Tenant of the terms, covenants and conditions of
this Lease, including the surrender of possession of the Premises to Landlord as
herein provided.

In lieu of a cash deposit, Tenant
may deliver the Security Deposit to Landlord in the form of a clean,
irrevocable, non-documentary and unconditional letter of credit (the "Letter
of Credit") issued by and drawable upon any commercial bank satisfactory
to Landlord, trust company, national banking association or savings and loan
association (the "Issuing Bank"), which has outstanding unsecured,
uninsured and unguaranteed indebtedness, or shall have issued a letter of credit
or other credit facility that constitutes the primary security for any
outstanding indebtedness (which is otherwise uninsured and unguaranteed), that
is then rated, without regard to qualification of such rating by symbols such as
"+" or "-" or numerical notation, "Aa" or better by Moody's
Investors Service and "AA" or better by Standard & Poor's Rating
Service, and has combined capital, surplus and undivided profits of not less
than $500,000,000. Such Letter of Credit shall (a) name Landlord as beneficiary,
(b) be in the amount of the Security Deposit, (c) have a term of not less than
one year, (d) permit multiple drawings, (e) be fully transferable by Landlord
without the payment of any fees or charges by Landlord, and (f) otherwise be in
form and content satisfactory to Landlord. If upon any transfer of the Letter of
Credit, any fees or charges shall be so imposed, then such fees or charges shall
be payable solely by Tenant and the Letter of Credit shall so specify. The
Letter of Credit shall provide that it shall be deemed automatically renewed,
without amendment, for consecutive periods of one year each thereafter during
the Term unless the Issuing Bank sends a notice (the "Non-Renewal Notice")
to Landlord by certified mail, return receipt requested, not less than 45 days
next preceding the then expiration date of the Letter of Credit stating that the
Issuing Bank has elected not to renew the Letter of Credit. Landlord shall have
the right, upon receipt of the Non-Renewal Notice, to draw the full amount of
the Letter of Credit, by sight draft on the Issuing Bank, and shall thereafter
hold or apply the cash proceeds of the Letter of Credit pursuant to the terms of
this Section. The Issuing Bank shall agree with all drawers, endorsers and bona
fide holders that drafts drawn under and in compliance with the terms of the
Letter of Credit will be duly honored upon presentation to the Issuing Bank at
an office location in Boston or another location acceptable to Landlord. The
Letter of Credit shall be subject in all respects to the Uniform Customs and
Practice for Documentary Credits (1993 revision), International Chamber of
Commerce Publication No. 500.

33

---

If Tenant defaults in the payment
or performance of any of the terms, covenants or conditions of this Lease beyond
the expiration of applicable notice and cure periods, if any, including the
payment of Annual Rent or Additional Rent, Landlord may apply or retain the
whole or any part of the cash Security Deposit or may notify the Issuing Bank
and thereupon receive all or a portion of the Security Deposit represented by
the Letter of Credit and use, apply, or retain the whole or any part of such
proceeds, as the case may be, to the extent required for the payment of any such
rent or any other sums as to which Tenant is in default including (a) any sum
which Landlord may expend or may be required to expend by reason of Tenant's
default, and/or (b) any damages or deficiency to which Landlord is entitled
pursuant to this Lease or applicable legal requirements, whether such damages or
deficiency accrues before or after summary proceedings or other reentry by
Landlord. If Landlord applies or retains any part of the Security Deposit,
Tenant, upon demand, shall deposit with Landlord the amount so applied or
retained so that Landlord shall have the full Security Deposit on hand at all
times during the Term. If Tenant shall fully and faithfully comply with all of
the terms, covenants and conditions of this Lease, the Security Deposit shall be
returned to Tenant after the expiration of the Term and after delivery of
possession of the Premises to Landlord in the manner required by this Lease.
Tenant expressly agrees that Tenant shall have no right to apply any portion of
the Security Deposit against any of Tenant's obligations to pay rent or other
sums due hereunder.

Upon a sale of the Lot or the
Building or any financing of Landlord's interest therein, Landlord shall
transfer the cash Security Deposit or the Letter of Credit, as applicable, to
the vendee or lender (if required by such lender). With respect to the Letter of
Credit, within five days after notice of such sale or financing, Tenant, at its
sole cost, shall arrange for the transfer of the Letter of Credit to the new
landlord or the lender (if required by such lender), as designated by Landlord
in the foregoing notice or have the Letter of Credit reissued in the name of the
new landlord or the lender. Provided that such cash Security Deposit or Letter
of Credit is transferred to the new landlord or lender, Tenant shall look solely
to the new landlord or lender for the return of such cash Security Deposit or
Letter of Credit and the provisions hereof shall apply to every transfer or
assignment made of the Security Deposit to a new landlord. Tenant shall not
assign or encumber or attempt to assign or encumber the cash Security Deposit or
Letter of Credit and neither Landlord nor its successors or assigns shall be
bound by any such action or attempted assignment, or encumbrance.

Notwithstanding any terms or
provisions of this Lease to the contrary, provided that there shall be no
default under this Lease beyond the expiration of applicable notice and cure
periods at the time, the Security Deposit shall be reduced to $299,587.50 (the
"Reduced Security Deposit") (i) within 30 days of the BroadVision Assignment
or (ii) within thirty (30) days of the date that BroadVision delivers an
unconditional guaranty to Landlord (in a form acceptable to Landlord) of all of
Tenant's obligations under this Lease, whenever arising, and BroadVision
otherwise meets (on the date of the execution and delivery of such guaranty) the
requirements for Landlord's consent to the BroadVision Assignment (except for
clause iii thereof) described in the third paragraph of Section 8.15

34

---

as if such guaranty were instead the BroadVision Assignment. If the reduction
of the Security Deposit is required under the prior sentence, Landlord shall
nevertheless not be obligated to deliver the portion of the security deposit
(i.e., $800,919.00) to be so reduced (or, if applicable, the original Letter of
Credit) to Tenant unless and until Landlord shall have received (i) if
applicable, a Letter of Credit meeting the above requirements of this Section
12.9 in the amount of the Reduced Security Deposit and (ii) a written direction
from both Interleaf, Inc. and BroadVision regarding the return of such funds,
which direction shall include wiring or delivery instructions and a release of
liability by such parties for the benefit of Landlord with respect to the return
of such amount of the Security Deposit.

Section 12.10.   
Waiver of Trial By Jury.  LANDLORD AND TENANT HEREBY WAIVE TRIAL BY
JURY IN ANY ACTION, PROCEEDING OR COUNTERCLAIM BROUGHT BY EITHER PARTY AGAINST
THE OTHER ON ANY MATTERS IN ANY WAY ARISING OUT OR CONNECTED WITH THIS LEASE,
THE RELATIONSHIP OF LANDLORD AND TENANT, TENANT'S USE OR OCCUPANCY OF THE
PREMISES, OR THE ENFORCEMENT OF ANY REMEDY UNDER ANY STATUTE, EMERGENCY OR
OTHERWISE. If Landlord commences any summary process proceeding against Tenant,
Tenant will not interpose any counterclaim of any nature or description in any
such proceeding (unless failure to impose such counterclaim would preclude
Tenant from asserting in a separate action the claim which is the subject of
such counterclaim), and will not seek to consolidate such proceeding with any
other action which may have been or will be brought in any other court by
Tenant.

Section 12.11.   
No Surrender or Release.  No act or thing done by Landlord or
Landlord's agents or employees during the Term shall be deemed an acceptance
of a surrender of the Premises, and no provision of this Lease shall be deemed
to have been waived by Landlord, unless such waiver is in writing and is signed
by Landlord, and any such waiver shall be effective only for the specific
purpose an in the specific instance in which given.

Section 12.12.   
No Representations.  Except as expressly set forth herein, Landlord
and Landlord's agents have made no warranties, representations, statements or
promises with respect to the Building, the Lot or the Premises and no rights,
easements or licenses are acquired by Tenant by implication or otherwise. This
Lease contains the entire agreement between the parties and all understandings
and agreements previously made between Landlord and Tenant are merged in this
Lease, which alone fully and completely expresses their agreement. Tenant is
entering into this Lease after full investigation and is not relying upon any
statement or representation made by Landlord not embodied in this Lease.

Section 12.13.   
No Money Damages.  Wherever in this Lease Landlord's consent or
approval is required, if Landlord refuses to grant such consent or approval,
whether or not Landlord expressly agreed that such consent or approval would not
be unreasonably withheld, Tenant shall not make, and Tenant hereby waives, any
claim for money damages (including any claim by way of set-off, counterclaim or
defense) based upon Tenant's claim

35

---

or assertion that Landlord unreasonably withheld or delayed its consent or
approval; and Tenant's sole remedy shall be to seek injunctive relief.

Section 12.14.   
Financial Statements.  Within ten (10) days after Landlord's
request, which request may be made from time to time during the Term, Tenant
shall deliver to Landlord the current audited financial statements of Tenant
with an opinion of a certified public accountant, including a balance sheet and
profit and loss statement for the most recent prior year, all prepared in
accordance with generally accepted accounting principles consistently applied.

Section 12.15.   
Tenant's Signage.  Subject to Tenant's receipt of all necessary
approvals therefore from all applicable governmental agencies (including,
without limitation, the City of Waltham) and subject to Landlord's review and
prior written reasonable approval of the size, location and design of such sign,
Tenant shall be allowed to install, at Tenant's sole cost and expense, a
single-tenant tenant identification monument sign in front of the Building (on
which Tenant shall have the exclusive right to maintain a Tenant identification
sign); provided, however, that if Tenant shall at any time lease in excess of
73,000 square feet at the Building, Tenant shall have the right to erect a sign
on the exterior of the Building facade facing Fifth Avenue in a location
designated by Landlord and having a design and size approved by Landlord. Upon
the expiration or sooner termination of the term of this Lease, Tenant shall
remove all such signage at its expense and shall pay for any damage caused to
the Building or the monument caused by the installation or removal of such
signage. Upon the expiration of the term, Landlord shall have the right to
direct Tenant to either remove the monument bearing such sign or to leave the
same for use by a future tenant.

Section 12.16.   
Intentionally Omitted.

Section 12.17.   
Renovation of Lobby and Cafeteria.  Landlord shall use reasonable
efforts to substantially complete the renovation of the existing Building lobby
and the existing cafeteria within sixty (60) days of the Term Commencement Date,
subject to the duration of any delays described in Section 12.5 and subject to
the duration of any delays caused by the failure of the existing tenant(s) of
the First Floor Premises to vacate the same on the dates scheduled for vacation
of the same.

Section 12.18.   
Satellite Dish.  Landlord hereby grants to Tenant a non-exclusive
and non-transferable license ("License"), coterminous with the term hereof
unless, at Landlord's election, earlier terminated due to Tenant's failure
to comply with the provisions of this Section 12.18, to use, after prior written
notice to Landlord, such area of the roof of the Building as shall be designated
by Landlord (so as to avoid interference with, to or from other current or
future users on the roof) for the installation and operation of a satellite dish
and connecting equipment (the "Satellite Dish"). Tenant shall pay a fee for
the License at the then prevailing market rate for such a License on the roof
the Building, as determined by Landlord from time to time. The Satellite Dish
shall be installed and maintained in accordance with plans and specifications
approved in writing by Landlord and such other reasonable requirements as
Landlord shall impose. The

36

---

provisions of this Lease shall apply to Tenant's use of the License
pursuant to this Section 12.18 just as if the License were part of the Premises
except that the License is non-exclusive and non-transferable, and is subject to
termination by Landlord in the event of Tenant's failure to comply with any
provision of this Lease related to the use of the License or upon the occurrence
of an Event of Default by Tenant under this Lease. The cost of any repair to any
damage to the Building caused by Tenant in connection with installation,
maintenance, repair, replacement or removal of the Satellite Dish shall be paid
by Tenant.

Tenant will save Landlord harmless
and will exonerate, defend and indemnify Landlord, from any against any and all
claims, liabilities and penalties, including reasonable attorneys' fees,
asserted by or on behalf of any person, firm corporation or public authority in
connection with the installation, operation, repair, maintenance, replacement or
removal of the Satellite Dish.

Tenant may have access to the roof
of the Building (accompanied by a representative of Landlord if Landlord so
requires) where necessary in connection with the installation, maintenance,
repair, replacement and removal of the Satellite Dish. Landlord shall have right
to cause Tenant to relocate, at Tenant's sole cost and expense, the Satellite
Dish to another portion of the roof of the Building by written notice delivered
to Tenant. Landlord shall not grant a license for the installation of a
satellite dish to another tenant of the Building that will materially interfere
with the operation of Tenant's satellite dish.

Section 12.19.   
Generator Pad.  Subject to Tenant's receipt of all necessary
approvals therefor from all applicable governmental agencies (including, without
limitation, the City of Waltham) and subject to Landlord's review and prior
written approval of the plans and the location for the same, Tenant shall have
the right to erect a concrete generator pad outside of the Building on the Lot
and operate a generator on such pad that shall serve the Premises exclusively;
provided, however, that the location of all interior Building connections,
piping and wiring to the same shall be subject to Landlord's prior written
approval, which Landlord may withhold in its sole discretion. Upon the
expiration or sooner termination of the term of this Lease, Tenant shall remove
the generator (but leave the generator pad) and, at Landlord's direction, all
piping and connections to the same, and Tenant shall repair all damage to the
Building caused by such removal.

Tenant will save Landlord harmless
and will exonerate, defend and indemnify Landlord, from any against any and all
claims, liabilities and penalties, including reasonable attorneys' fees,
asserted by or on behalf of any person, firm corporation or public authority in
connection with the installation, operation, repair, maintenance, replacement or
removal of the generator.

Section 12.20.   
Confidentiality Agreement.  Tenant and Landlord agree that all of
the terms and provisions of this Lease shall be kept and treated as confidential
by each party and each party's partners, officers, directors, employees,
representatives and agents. Neither Landlord nor Tenant may divulge or disclose,
at any time, any terms or provisions of this Lease to any person, entity, firm,
organization or corporation, except for disclosures

37

---

made to comply with law and except for disclosures made to (i) each party's
employees, directors, representatives, attorneys or agents obligated to maintain
the confidentiality thereof for the sole purposes of interpreting the terms and
provisions of this Lease and (ii) to prospective lenders, purchasers, assignees,
or sublessees. In the event that either party shall be required to disclose any
of the terms and provisions of this Lease in connection with any court,
administrative or other governmental proceeding, such party shall be permitted
to do so provided that such party has provided the other party with prompt
notice of such requirement so that the other party has had an opportunity to
seek an appropriate protective order. Each party agrees that a breach of this
confidentiality provision, or such a breach by any person to whom it has
disclosed any of the terms and provisions hereof, will cause irreparable harm to
the non-disclosing party.

WITNESS the execution hereof under
seal as of the day and year first above written.

| | LANDLORD:                        | 
| | -------------------------------- | 
| |                                  | 
| | VEF III FUNDING, LLC, a Delaware | 
| | limited liability company        | 
| |                                  | 
| | By:                              | 
| |                                  | 
| |                                  | 
| |                                  | 
| |                                  | 
| |                                  | 
| |                                  | 
| |                                  | 
| |                                  | 
| |                                  | 
| |                                  | 
| |                                  | 
| | TENANT:                          | 
| |                                  | 
| | INTERLEAF, INC.                  | 
| |                                  | 
| | By:                              | 
| |                                  | 
| | Name:                            | 
| |                                  | 

38

---

SCHEDULE 1 LANDLORD'S WORK

First Floor Second Stage Premises, Second Floor Premises, Third Floor
Premises and Fourth Floor Premises

|A.                               |  | Reapplication of fireproofing in accordance with
      Landlord's Building fireproofing program.                                                                                  
|-------------------------------- |  | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|First Floor First Stage Premises
|A.                               |  | Erection of partition walls to demise First Floor First
      Stage Premises from adjacent space on First Floor of the Building to be
      utilized by DOME imaging systems, inc.
|B.                               |  | Reapplication of fireproofing in accordance with
      Landlord's Building fireproofing program.                                                                                  

39

---

EXHIBIT A

40

---

EXHIBIT B

41

---

EXHIBIT C

42

---

EXHIBIT D

43

---

EXHIBIT E

44

---

EXHIBIT F

45

---

EXHIBIT A:               
Plan of Premises E



EXHIBIT B:               
Description of Lot



EXHIBIT C:               
Parking Area



EXHIBIT D:               
Cleaning Specifications



EXHIBIT E:               
Rules and Regulations



46

---