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                                                                    Exhibit 10.1

                              AMENDMENT #1 TO LEASE

1.       Parties.

         This Amendment, dated for identification purposes as of ________, 2003,
is between 400 River Limited Partnership ("Landlord") and NaviSite, Inc.,
("Tenant"). The "Effective Date" is the date that this Amendment is signed and
delivered by Landlord and Tenant and the other signatories hereto and conditions
to its effectiveness agreed to by the parties in writing (if any) have been
satisfied or waived.

2.       Recitals.

         2.1.     Landlord and Tenant have entered into a Lease, dated as of
5/14/1999, for premises known as 400 Minuteman Road in Andover, Massachusetts
(as now or hereafter amended or extended, the "Lease"). Unless otherwise
defined, terms used in this Amendment have the same meanings as those used in
the Lease. The Lease is guaranteed pursuant to a Guaranty of Lease made by
ClearBlue Technologies, Inc. and ClearBlue Atlantic LLC in favor of Landlord (as
now or hereafter amended or extended, the "Lease Guaranty").

         2.2      (a) Tenant no longer needs its space on the 2nd floor of the
Building and has vacated that space. In order to effectively reduce Tenant's
rental obligations under the Lease, the parties have agreed that Landlord will
enter (or has entered) into a direct lease between Landlord and WSI Corporation
("WSI"), dated 6/9/2003, for part of the 2nd floor space (as now or hereafter
amended or extended the "WSI Lease"). Landlord has also agreed to relieve Tenant
of certain other ongoing obligations under the Lease. Landlord and Tenant would
have preferred that WSI sublease directly from Tenant, but WSI was unwilling, so
in order to facilitate the transaction, Landlord agreed to enter into the WSI
Lease provided that Tenant enters into this Amendment and certain other related
documents as described herein. Even though the WSI Lease is not a sublease but
is a direct lease from Landlord, and Tenant is not a party to the WSI Lease, as
more particularly described in this Amendment certain portions of this Amendment
are included in order to put Landlord in the position it would have been in if
WSI instead had subleased directly from Tenant. Tenant has received a copy of
and has reviewed and understands the WSI Lease.

                  (b) The tenant under the WSI Lease and its successors, assigns
or sublessees is called the "WSI Tenant." The space leased under the WSI Lease
on the 2nd Floor of the Building is called the "WSI Space," and Tenant will
surrender possession of the WSI Space and certain other space described below
during the term of the WSI Lease. The initial WSI Space is agreed to contain
66,069 square feet of rentable area and is shown in Exhibit "A-1" hereto.
Landlord also will return to Tenant the Letter of Credit described in Section
24.17(a) of the Lease (i.e., Irrevocable Standby Letter of Credit No. 3053688,
dated 1/27/2003, issued by Bank of America to The Bank of Nova Scotia as
beneficiary) and that Tenant no longer will be required to supply the Letter of
Credit as security under the Lease, although the Additional Security supplied by
Tenant as described in Section 24.17(A) of the Lease will not be affected. As
consideration for being relieved of that ongoing obligation and other ongoing
obligations under the Lease, as more particularly described below Tenant will
pay to Landlord One Million Four Hundred Thousand Dollars ($1,400,000) in
immediately available funds (the "Initial Funds").

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                  (c) As more particularly described below, on or before the
Effective Date, Tenant will cause ClearBlue Finance, Inc. ("CBT Finance"), an
Affiliate of Tenant, to irrevocably convert that certain note from Tenant with
an initial principal balance of approximately $45,093,333, together with all
accrued and unpaid interest thereon (the "Note") into common stock in Tenant.

                  (d) To accomplish these and other matters, for good and
valuable consideration, the receipt and sufficiency of which are acknowledged,
the parties agree and the Lease is amended as follows as of the Effective Date
hereof, notwithstanding anything to the contrary:

3.       Amendments.

         3.1      (a) Tenant confirms and agrees that: as of the Effective Date
it has vacated and surrendered possession of the WSI Space and the Common Area
(defined below) and abandoned any personal property therein in favor of
Landlord; Landlord is free to lease the WSI Space to the WSI Tenant under the
WSI Lease; and the Lease and Tenant's rights, duties and obligations under the
Lease with respect to the WSI Space and the Common Area are terminated as of the
Effective Date, except to the extent described below and elsewhere in this
Amendment, and the Premises as defined in and used under the Lease will be
redefined to consist only of the "Remaining Premises" (defined below). The
"Project" will be deemed to mean the Land and all improvements now or hereafter
constructed on the Land, including the Building (the original definition of the
Premises). Tenant will remain responsible for Liabilities that it is responsible
for under the Lease that were incurred, or that arise from Tenant's defaults,
acts or omissions that occurred, before the Effective Date with respect to the
WSI Space and/or the Common Area (e.g., for hazardous substances in those areas
that were released by Tenant, if any, or for repairs that Tenant should have but
didn't perform in or for those areas as required under the Lease, if any). To
the actual knowledge of Landlord, Tenant is not in default under the Lease as of
this date. To the actual knowledge of Tenant, Landlord is not in default under
the Lease as of this date.

                  (b) The portion of the Project that Tenant has not vacated and
surrendered hereunder is designated in Exhibit "A-1" hereto as the "Remaining
Premises," and is agreed to contain a total rentable area of 86,931 square feet
(76,500 s.f. on the ground floor of the Building and 10,431 s.f. on the 2nd
floor of the Building).

                  (c) "Common Area" means all areas of the Project other than
the Remaining Premises and the WSI Space, including, without limitation, all
areas outside of the Building (including parking areas and access roadways), the
exterior of the Building and the rooftop, and the designated lobby areas,
loading docks, elevators and stairwells on the first and second floors. Except
during emergencies or by reason of force majeure or necessary maintenance,
repair or construction, and subject to the other terms of this Lease, Landlord's
exercise of its rights in connection with the Common Area as described below in
this Section will not ever prevent Tenant from having access to or beneficial
use of its Remaining Premises, at least one loading dock, and its parking rights
as granted in this Amendment, but subject to the foregoing such exercise will
not under any circumstances require Landlord to compensate Tenant, result in any
Liabilities to Landlord, entitle Tenant to abate rent, or otherwise reduce
Tenant's Lease obligations, although any other rights that Tenant may have to
abate rent for other reasons as may be specifically provided elsewhere in the
Lease [e.g., under Section 16.3 in case of casualty

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damage] are not affected by this clause. Subject in all cases to the foregoing,
Landlord reserves all rights in connection with the Common Area, including,
without limitation, the right to modify the Common Area (provided that the
modification does not cause the Premises to be in violation of applicable Laws)
and promulgate reasonable rules and regulations with respect thereto, to allow
tenants of the Building and certain of their Affiliates to use the Common Area,
and to place certain portions of the Common Area off limits to tenants of the
Building and/or their Affiliates. Landlord reserves the space above hung
ceilings, below the floor and within the walls of the Premises, and the right to
install, relocate, remove, use, maintain, repair and replace Systems and
Equipment within or serving the Premises, provided that except in cases of
emergency or to protect life, safety or health, Landlord will take commercially
reasonable precautions not to materially adversely affect the operation,
security or use by Tenant of the data center on the ground Floor of the
Remaining Premises. Without limiting the generality of the foregoing, Landlord
and the WSI Tenant and their Affiliates will have the right to install, repair
and maintain Systems and Equipment in the MDF Rooms and MER Rooms (collectively,
the "MDF Rooms") as designated in Exhibit "A-1" hereto and to have access
thereto, and to use the fibre telecommunications cable and connections thereto
and services provided thereby, whether provided by MCI, AT&T or other providers,
subject to the procedures described in Section 24.2 of the Lease, and except in
cases of emergency or to protect life, safety or health, those parties will take
commercially reasonable precautions not to materially adversely affect the
operation, security or use by Tenant of the data center on the ground Floor of
the Remaining Premises.

         3.2      (a) Effective as of the Rent Commencement Date under the WSI
Lease, the base rent and Tenant's Percentage of Taxes, Operating Costs and
Landlord's insurance premiums payable by Tenant under the Lease will be modified
as set forth in Exhibit "D-1" hereto.

                  (b) Starting as of the Rent Commencement Date under the WSI
Lease, and for each calendar month or partial month during the remaining term of
the Lease for as long as it is in effect, if Tenant is not in monetary default,
unless prevented by applicable Laws (e.g., Bankruptcy Laws or other court
order), Landlord will pay to Tenant the Backup Power Costs (defined in Section
3.8(d) below) actually received by Landlord from the WSI Tenant or its Guarantor
under the WSI Lease allocable to that month or partial month (the "WSI
Payments") within five (5) business days after Landlord's receipt thereof. For
as long as the WSI Lease is in effect, and until and unless the WSI Tenant
defaults thereunder, Landlord will not intentionally waive the WSI Tenant's
obligations to pay the WSI Payments under the WSI Lease. Landlord's obligations
in this clause are subject to Section 3.2(d) below, and if there are any
conflicts, Section 3.2(d) will control.

                  (c) Provided that Tenant is not in default under the Lease and
the WSI Lease is still in full force and effect, if during the Lease term the
WSI Tenant is in default under the WSI Lease for failure to pay the WSI Payments
as required after the expiration of applicable notice and cure periods
thereunder, and if Landlord does not cause the WSI Payments owed to Tenant to be
paid within thirty (30) days after an additional written notice from Tenant,
Tenant, as its sole right and remedy (except as provided in Section 3.2(d)
below), may cease to provide the Backup Power System to the WSI Tenant until
such amounts are paid in full. Nothing herein or elsewhere is meant to imply
that Landlord has any obligation to pay Backup Power Costs to Tenant, except to
pass on to Tenant the WSI Payments actually received by Landlord as and to the
extent required under Section 3.2(b) above.

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                  (d) If Landlord receives WSI Payments from the WSI Tenant but
fails to pay them over to Tenant as and to the extent required under Section
3.2(b) above within thirty (30) days after written notice from Tenant, Tenant's
sole right and remedy will be to bring an action against Landlord to recover
those WSI Payments received but not paid by Landlord.

                  (e) On the Effective Date, Tenant will pay the Initial Funds
to Landlord in full in addition to any rent due under the Lease (the Initial
Funds are not intended to be rent under the Lease, but if Tenant fails to pay
those amounts Landlord will have the same rights and remedies as it would have
if Tenant failed to pay rent), and concurrently therewith Landlord will cause
the Letter of Credit to be returned to Tenant undrawn, and thereafter Section
24.17 and all references in the Lease to the Letter of Credit, the Letter of
Credit Loan and the LC Amount will be deemed deleted from the Lease, and Tenant
no longer will be required to post any further Letter of Credit or deliver any
further security under Section 24.17 of the Lease. However, Tenant's continuing
obligations and Liabilities under Section 24.17A of the Lease and with respect
to the Additional Security and the Additional Letter of Credit (if any) referred
to therein will not be affected.

                  (f) [Intentionally Omitted]

                  (g) On or before the Effective Date, Tenant will cause CBT
Finance to irrevocably convert to common shares in Tenant the Note together with
any accrued or imputed interest thereon directly or indirectly held by CBT
Finance or any of its Affiliates. Tenant represents and warrants that the Note
is the sole remaining debt of Tenant that was acquired directly or indirectly
from CMGI, Inc. or Hewlett-Packard Financial Services or any of their respective
Affiliates This conversion will comply with applicable Laws and the terms of the
Note and the documents related thereto, and on or before the Effective Date
Tenant will deliver to Landlord such written evidence as Landlord may reasonably
request in order to verify that this conversion has occurred in compliance with
this Section.

         3.3      Section 1.3 of the Lease is amended by adding the following at
the end:

                  "This wiring will become Landlord's property on the
                  termination of this Lease (if and to the extent that it is not
                  already Landlord's property) and Tenant will not remove this
                  wiring."

         3.4      Section 2(d) of the Lease is deleted.

         3.5      Article 3 of the Lease is deleted and the following is
substituted:

                  "3. Possession and Surrender of Remaining Premises. Subject to
                  the rest of this Article 3, when this Lease terminates Tenant
                  will remove from the Remaining Premises all of Tenant's signs,
                  movable trade fixtures, movable furniture, movable computer,
                  and other movable telecommunications equipment (and wiring
                  integral to such computers and equipment), inventory and its
                  other movable personal property ("Tenant's Movable Property"),
                  which will include Tenant's computer network switchgear and
                  associated cabling, and Tenant will repair any damage caused
                  by said removal; provided, however, that Tenant will not have
                  the right or obligation to remove any ceilings, or any of
                  Tenant's Moveable

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                  Property or other equipment or wiring if it would damage the
                  exterior or structure of the Building or if it is integral to
                  or necessary for the proper functioning of the Systems and
                  Equipment in the Building (in Landlord's reasonable
                  judgement), all of which will be deemed fixtures and included
                  in "Non-Removed Property" as defined below. Tenant may, but
                  will not be required, to remove Tenant's Movable Property from
                  the data center area on the ground floor of the Building, and
                  if Tenant does not remove the same it will be deemed to be
                  Landlord's property. Tenant's Movable Property does not
                  include, and the following will be excluded from Tenant's
                  Movable Property and will not be removed from the Building by
                  Tenant (collectively, "Non-Removed Property"): HVAC, plumbing,
                  cafeteria, kitchen or life safety Systems and Equipment,
                  chillers, raised flooring, telephone switches, switch gear and
                  associated cabling (not including Tenant's computer network
                  switchgear and associated cabling, which is part of Tenant's
                  Moveable Property to the extent described above), and the
                  standby generators, paralleling gear, UPS equipment,
                  batteries, monitoring, control and distribution equipment and
                  associated Systems and Equipment (collectively, the "Backup
                  Power System"), all other electrical and power distribution
                  equipment and associated Systems and Equipment, and all
                  Systems and Equipment associated with or necessary for the
                  proper functioning of the foregoing items, all of which
                  irrevocably will be deemed to be fixtures and part of the
                  realty that will remain after the expiration or termination of
                  this Lease, and Landlord may allow the WSI Tenant and other
                  occupants of the Building to tap into and use such items
                  during the Lease term, provided that they do so in a
                  commercially reasonable manner and after consultation with
                  Tenant's facilities personnel. Tenant will not have the right
                  to remove, lien, hypothecate or subject Non-Removed Property
                  to a security interest or otherwise Transfer any of the
                  Non-Removed Property or any other fixtures in the Building
                  that are deemed to be part of the realty or any interest
                  therein, nor will Tenant have any right to remove (or any
                  other rights in) Landlord's Furniture as described in Exhibit
                  "H" hereto. Tenant's Movable Property remaining after
                  termination or expiration of the Lease will be deemed
                  abandoned and Landlord may keep, sell, destroy or dispose of
                  it without incurring any Liabilities to Tenant. Upon
                  termination of the Lease: (a) with respect to areas of the
                  Remaining Premises other than the data center on the ground
                  floor, Tenant will repair all damage and surrender the
                  Remaining Premises broom clean and in good order in its
                  now-existing condition and repair (i.e., as of the Effective
                  Date of this Amendment, and not in the condition and repair
                  existing on the Rent Commencement Date of the Lease), normal
                  wear and tear excepted; and with respect to Tenant's data
                  center on the ground floor of the Remaining Premises, Tenant's
                  only obligation will be to repair damage caused by Tenant to
                  the exterior or structure of the Building or the Systems and
                  Equipment."

         3.6      In Section 7.1 of the Lease, the definition of Operating Costs
will be amended as follows: the word "Premises" will be replaced by the word
"Project" as defined in this Amendment; costs and expenses incurred in
connection with the Common Area will be included

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therein; and starting on the first day of the 30th month after the Rent
Commencement Date under the WSI Lease, the management fee (or fee in lieu
thereof) will be three percent (3%) of all scheduled rent payable by Tenant and
any other tenants or licensees of the Project (including, without limitation,
the WSI Tenant), subject to the inclusions and exclusions described in Section
7.1.

The definition of Operating Costs payable under the WSI Lease (which includes
Landlord's insurance costs) may differ in some respects from the definition of
Operating Costs under the Lease (as defined above), and so it's possible that
the Operating Costs and insurance costs payable under the WSI Lease may be less
than what Landlord would have received if Tenant had continued to lease the WSI
Space. To prevent Landlord from being penalized, starting on the first day of
the 30th month after the Rent Commencement Date under the WSI Lease and for the
remainder of the Lease term, Tenant will pay to Landlord any shortfall that
Landlord may incur if the share of Operating Costs and Landlord's insurance
costs payable under the WSI Lease is less than it would have been if the
definitions of Operating Costs and Landlord's insurance costs payable under the
WSI Lease were the same as Tenant's under the Lease. This shortfall (if any)
will be paid by Tenant as additional rent each month (or less frequently as may
be billed by Landlord) and in addition to any other amounts payable by Tenant
under the Lease.

                  -Remainder of Page Intentionally Left Blank-

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         3.7      Article 7 of the Lease is further amended by adding the
following as a new Section 7.3:

                  "7.3 Audit Right. No more than once during each twelve
                  (12)-month period during the term, provided that Tenant
                  delivers written notice to Landlord within sixty (60) days
                  after receipt of the annual Operating Cost and insurance
                  statements and has paid the amount of those statements and is
                  not in default, Tenant will have the right, at its sole cost,
                  to audit with an independent certified public accountant the
                  Operating Costs and insurance costs charged to Tenant for the
                  Lease Year to which such statements apply and the WSI Payments
                  paid to Tenant for that Lease Year. The auditors must be
                  compensated on an hourly basis for time spent and not pursuant
                  to a "contingent fee" arrangement of any type. This audit will
                  take place only at the Project (or at Landlord's election
                  elsewhere in Minuteman Park) during Landlord's normal business
                  hours on at least two (2) weeks' prior written notice, in a
                  manner that will not unreasonably disrupt Landlord's business
                  operations, and for a period not to exceed five (5) business
                  days. Landlord will provide the relevant records, books and
                  documents to such location at its expense. Landlord will not
                  be required to provide analyses or comparisons for Tenant, but
                  will on request provide, line item breakdowns of Operating
                  Costs and insurance costs and invoices therefor (to the extent
                  in Landlord's possession) for the applicable Lease Year and
                  the WSI Payments received. Copying of these materials will not
                  be permitted, but Tenant's auditors may make notes. Tenant
                  agrees to keep strictly confidential the results of its audits
                  and any information obtained in connection therewith, as well
                  as any claims, negotiations, proceedings or settlements with
                  Landlord, and will cause its auditors and other Affiliates to
                  comply with these confidentiality requirements. As a condition
                  to conducting an audit, Landlord may require Tenant and its
                  auditors and other Affiliates to sign confidentiality
                  agreements for this purpose. If an error has been made in the
                  billing of Operating Costs or insurance costs, or the payment
                  of the WSI Payments, whether in favor of Landlord or Tenant,
                  the sole right and remedy of the parties will be to adjust the
                  amount of the discrepancy in cash within thirty (30) days (and
                  if Landlord owes amounts to Tenant Landlord may, at its
                  option, credit those amounts against the rent next due from
                  Tenant)."

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         3.8      Article 10 of the Lease is amended by adding an "(a)" in front
of the existing paragraph and by adding the following at the end as new
paragraphs:

                  "(b) During the term of the WSI Lease Landlord will have the
                  sole right to determine the utility providers for the Project,
                  and starting as of the Rent Commencement Date under the WSI
                  Lease (or earlier at Landlord's option) Landlord will become
                  the metered electrical client for the Project, and Tenant will
                  pay only the electrical costs charged by the utility provider
                  associated with the Remaining Premises and the Systems and
                  Equipment serving the Remaining Premises (as determined by
                  meter, submeter, Intellimeter or the equivalent, the cost of
                  which will be payable by Tenant) and its Tenant's Percentage
                  of the electrical costs charged by the utility provider for
                  the Common Area. If the utility provider ever agrees to bill
                  Tenant directly for its share of electrical costs for the
                  Remaining Premises by meter, submeter, Intellimeter or
                  otherwise, at Landlord's written election Tenant again will
                  become the direct client of the utility provider for such
                  costs, and Tenant will cooperate and promptly execute such
                  documents as may be necessary to accomplish the foregoing.

                  (c) Tenant acknowledges and agrees that throughout the term of
                  the WSI Lease the WSI Tenant will be permitted at all times to
                  tap into the Backup Power System in a commercially reasonable
                  manner and after consultation with Tenant's facilities
                  personnel, and thereafter to use the Backup Power System.
                  Without limiting the generality of the foregoing or the terms
                  of Section 12.2, provided that the WSI Tenant does not default
                  in its obligation to pay its pro rata share of the Backup
                  Power Costs as required in Subsection (c) below, during the
                  Lease term Tenant will supply the WSI Tenant with the full
                  benefits of the Backup Power System (including, without
                  limitation, all monitoring functions), keep the Backup Power
                  System in good order, condition and repair and fully
                  operational at all times (subject to casualties or similar
                  events beyond Tenant's control, in which case full operations
                  will be restored by Tenant as soon as reasonably possible),
                  and continue to test, repair and maintain the Backup Power
                  System pursuant to commercially reasonable and customary
                  contracts for periodic testing, repair and maintenance with
                  representatives of the applicable equipment manufacturers of
                  the Backup Power System or their successors. Tenant will keep
                  on file at the Remaining Premises those contracts and all
                  documents related thereto or to the Backup Power System,
                  including, without limitation, invoices and bills, testing,
                  monitoring, repair and maintenance records, reports, analyses,
                  and correspondence to or from the equipment manufacturers and
                  other contractors (collectively, the "Backup Power Records').
                  Representatives of Landlord and/or the WSI Tenant will have
                  the right to inspect the Backup Power System, and on at least
                  twenty-four (24) hours' prior notice to Tenant to review and
                  copy the Backup Power Records at the Remaining Premises.

                  (d) For as long as the WSI Tenant uses the Backup Power System
                  to provide Backup Power to the WSI Space during the Lease
                  term, each

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                  month Tenant will bill the WSI Tenant (with concurrent copies
                  to Landlord) for the WSI Tenant's pro rata share of the
                  reasonable, bona fide, out-of-pocket costs actually incurred
                  by Tenant to unaffiliated third parties to test, repair,
                  maintain and operate the Backup Power System and to purchase
                  diesel fuel and other necessary supplies for the backup
                  generators and the rest of the Backup Power System
                  (collectively, the "Backup Power Costs") allocable to that
                  period. Tenant will be responsible for paying the Backup Power
                  Costs when due to the appropriate parties, with reimbursement
                  from the WSI Tenant as described below. The WSI Tenant's pro
                  rata share of the Backup Power Costs will be deemed to be 8.3%
                  of the Backup Power Costs fairly allocable to the backup
                  generators and 7% of the costs fairly allocable to the UPS.
                  Tenant will include with each bill invoices for and a
                  line-item breakdown of the Backup Power Costs incurred and the
                  allocation required above, and the WSI Tenant will have thirty
                  (30) days after receipt of each monthly bill to pay its share
                  of the Backup Power Costs directly to Tenant (or to Landlord
                  for payment to Tenant). Landlord will have the right, but
                  absolutely no obligation, to pay to Tenant, and thus cure, all
                  or any part of the unpaid Backup Power Costs (or any portions
                  of the other unpaid WSI Payments or other amounts) owed by the
                  WSI Tenant."

         3.9      Section 12.1 of the Lease is amended by adding the following
at the end:

                  "Starting on the Rent Commencement Date under the WSI Lease
                  and until the termination of the WSI Lease, Landlord also will
                  be responsible for the cleaning, repair and maintenance of the
                  Common Area (but not the Systems and Equipment in the Common
                  Area, which will continue to be Tenant's responsibility) and
                  the elevators."

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         3.10     Section 12.2 of the Lease is deleted and the following is
substituted:

                  "12.2 Tenant's Obligations/Backup Power System.

                  (a) Except for Landlord's obligations in Section 12.1 and the
                  repair and maintenance obligations of the WSI Tenant with
                  respect to the WSI Space under the WSI Lease, and in addition
                  to the repair and maintenance obligations of Tenant in Section
                  12.1, Tenant will at its cost maintain and repair the
                  Remaining Premises and all Systems and Equipment serving the
                  Project, whether inside or outside the Remaining Premises or
                  the WSI Space or the Common Area, including, without
                  limitation, the life safety, HVAC, plumbing, sanitary and
                  sewer, and electrical Systems and Equipment, the Non-Removed
                  Property (including the Backup Power System) and Tenant's
                  Moveable Property, in a first-class manner (including
                  replacement thereof if and when necessary), and keep them in
                  good order and condition (except to the extent otherwise
                  requested by Landlord in writing). In furtherance of Tenant's
                  maintenance and repair obligations, Landlord will assign to
                  Tenant, or cooperate in a commercially reasonable manner with
                  Tenant in enforcing, any guarantees or warranties of
                  Landlord's that are applicable to the Building and the Systems
                  and Equipment. Whether or not Tenant is in default, if
                  Landlord in good faith believes that Tenant has not repaired
                  or maintained as required above, or has not performed its
                  obligations as required in Section 10 above, Landlord will
                  send written notice thereof to Tenant, and if Tenant fails to
                  cure within fifteen (15) days thereafter, in addition to any
                  other rights and remedies it may have Landlord will have the
                  right to contract with outside contractors to repair and
                  maintain all or parts of the Project and/or the Systems and
                  Equipment that Tenant is otherwise required to repair and
                  maintain, and if Landlord does so, Tenant will pay the
                  reasonable costs thereof to Landlord within fifteen (15) days
                  after receipt of a bill or invoice from Landlord and Landlord
                  and such contractors and their respective Affiliates will have
                  such access to the Remaining Premises as they may deem
                  reasonably necessary to perform such functions."

         3.11     Section 13.1 of the Lease is amended by adding the following
at the end:

                  "Notwithstanding anything to the contrary, but without
                  limiting the generality of the foregoing, Tenant will not have
                  the right to modify or reconfigure or perform Alterations that
                  would adversely affect the continuous and proper functioning
                  of the MDF Rooms or the Backup Power System or any Systems and
                  Equipment outside (or that serve areas outside) the Remaining
                  Premises."

         3.12     Section 13.5 of the Lease is amended by adding the following
at the end:

                  "Notwithstanding the foregoing or anything else to the
                  contrary, but without otherwise changing the restrictions on
                  Tenant's use of the roof to install telecommunications
                  equipment: Tenant will cooperate with and

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                  permit the WSI Tenant to install telecommunications equipment
                  as permitted and in the areas reserved for the WSI Tenant
                  under the WSI Lease as set forth in Exhibit "H-1" hereto (and
                  Landlord may relocate one of Tenant's existing dish/antenna
                  installations thereon to a different rooftop location as shown
                  in Exhibit "HH" hereto); Tenant will not install any new
                  equipment in the areas of the roof and the Land that are
                  reserved for the initial or future telecommunications
                  equipment of the WSI Tenant, nor any telecommunications
                  equipment that includes C-band transmitting equipment or that
                  adversely interferes with the functioning of the
                  telecommunications equipment permitted to be installed by the
                  WSI Tenant under the WSI Lease, nor will Tenant permit any of
                  its existing equipment to be used for C-band transmissions;
                  and Tenant will take commercially reasonable steps to reduce
                  as much as reasonably possible, or eliminate, interference
                  with telecommunications equipment installed by the WSI Tenant
                  (although the parties do not necessarily contemplate that
                  there will be any interference). While on the roof, Tenant and
                  its Affiliates must walk on walking pads placed on the roof,
                  and not on the roof itself. Tenant and its contractors will be
                  granted both internal and external access to the rooftop for
                  the purposes described in this Section 13.5 subject to
                  Landlord's reasonable rules and regulations as to access and
                  the other terms of this Section and the rest of this Lease,
                  and provided further that Tenant will indemnify Landlord and
                  its Affiliates for and hold them free and harmless from all
                  damage and other Liabilities resulting directly or indirectly
                  from such access."

         3.13     Article 13 of the Lease is further amended by adding the
following as a new Section 13.6:

                  "13.6 Conversion of Portions of Tenant's Remaining Premises to
                  Office Space. Subject to the following, the rest of this
                  Article 13 and the rest of this Lease (but not Section
                  13.1(e), which will not apply), Tenant will have the right to
                  convert portions of the interior of the Remaining Premises on
                  the Ground Floor from their current use as a data center to
                  office use (the space so converted is called the "Office
                  Space"). The Office Space will not include the MDF Rooms as
                  designated in Exhibit "A-1" hereto or any part of the Common
                  Area or the Remaining Premises on the 2nd Floor. Tenant will
                  employ only licensed mechanical engineers, architects and
                  contractors selected by Tenant and subject to Landlord's
                  approval, which will not be unreasonably withheld or delayed,
                  for the design and construction of the Office Space, and will
                  construct the Office Space in accordance with the terms of
                  this Lease and the plans, specifications and recommendations
                  approved by Landlord in accordance with this Lease, and
                  subject to compliance with applicable Laws. Tenant will be
                  solely responsible for the timely payment of all fees and
                  costs for said engineers, architects and contractors, and for
                  the reasonable costs of any engineers or architects hired by
                  Landlord to review Tenant's plans and specifications and
                  supervise such work, and all other costs and other Liabilities
                  in connection with the design and construction of the Office
                  Space, and will indemnify Landlord and its Affiliates therefor
                  and defend and hold them harmless therefrom."

                                       11
<PAGE>

         3.14     Section 14.2 of the Lease is amended by replacing "tenants or
occupants of Minuteman Park" in the 6th line with "tenants or occupants of the
Building or elsewhere in Minuteman Park".

         3.15     Section 15.2 of the Lease is deleted and the following is
substituted:

                  "15.2 Parking. During the Lease term, at no additional cost to
                  Tenant (other than Tenant's share of Taxes, insurance and
                  Operating Costs from time to time), Tenant may park in
                  accordance with applicable Laws the number of passenger cars
                  equal to 150 (allocable to the Ground Floor portion of the
                  Remaining Premises) plus 3 cars for each 1,000 square feet of
                  agreed rentable area in the 2nd floor space of the Remaining
                  Premises (i.e., currently 32 cars for 10,431 s.f.) in assigned
                  spaces or on a non-exclusive basis or a combination thereof,
                  as determined by Landlord, in the parking areas of the Project
                  designated by Landlord from time to time for Tenant's parking
                  (Tenant's current parking areas are shown in Exhibit "A-1").
                  Landlord may reasonably: change signs, lanes and the direction
                  of traffic within the parking areas; change, or add parking
                  spaces or areas devoted to parking for Tenant's use; allow
                  free parking or parking with a validation, valet, sticker or
                  other system; promulgate rules and regulations; and take any
                  other actions deemed necessary by Landlord, provided that
                  Tenant always will have access to its number of parking spaces
                  (except to the extent that access is prevented by force
                  majeure or necessary repairs and maintenance). Tenant will not
                  park in spaces assigned to other tenants or reserved for
                  visitor parking. If Tenant does not use all of its parking
                  spaces, Landlord may allow others to use those spaces at no
                  charge, subject to Tenant's right to reclaim those spaces
                  immediately as and when legitimately needed for Tenant's
                  parking.

                  Subject to the foregoing, if Tenant converts a portion of the
                  Ground Floor portion of the Remaining Premises to Office Space
                  as described in Section 13.6, when the Office Space is
                  completed, the total number of cars that Tenant is permitted
                  to park will increase to be equal to the following: 3 cars for
                  each 1,000 square feet of area in the Office Space and the 2nd
                  Floor portion of the Remaining Premises; and 1.96 cars for
                  each 1,000 square feet of area in the rest of the Remaining
                  Premises. However, even if Office Space is created, this
                  additional parking will not be granted in connection with any
                  Office Space created for up to one hundred fifty (150)
                  employees or other personnel occupying the Ground Floor
                  portion of the Remaining Premises. As a purely hypothetical
                  example, if 20,000 square feet of Office Space is created to
                  accommodate Tenant's initial 150 employees, and 30,000 square
                  feet of Office Space is created to house 100 additional
                  employees, all on the Ground Floor of the Remaining Premises,
                  Tenant will have the right to park 213 cars (90 cars for the
                  30,000 s.f. Office Space created for the 100 additional
                  employees on the Ground Floor, 32 cars for the 2nd Floor
                  space, and 91 cars for the rest of the 46,500 s.f. Ground
                  Floor space in the Remaining Premises)."

         3.16     Section 16.1 of the Lease is amended by replacing "Tenant's
Property" in the 10th

                                       12
<PAGE>

line with "Tenant's Moveable Property, the Non-Removed Property, any other
property of Tenant".

         3.17     The following shall be added to the Lease as a new Section
18.8:

                  "18.8 Collocation Activities Not A Transfer. Notwithstanding
                  anything in this Lease to the contrary, the following
                  activities (collectively, "Collocation Activities") shall not
                  constitute a Transfer of the Lease or the Remaining Premises,
                  Tenant shall not be required to secure Landlord's consent
                  prior to conducting Collocation Activities, and Tenant shall
                  not, as a consequence of conducting Collocation Activities, be
                  required to pay Landlord any excess or "bonus" rent to the
                  extent received therefrom (and revenue received by Tenant from
                  Collocation Activities will be exempt from the applicable
                  provisions in Section 18.7 hereinabove), provided that in all
                  cases the Collocation Activities are otherwise subject to and
                  do not conflict with all of the terms of this Lease and do not
                  involve the occupancy of space in the Remaining Premises by
                  personnel other than for the sole purposes set forth in
                  Section 18.8(c):

                  (a) The placement of computer equipment, servers, routers and
                  other telecommunications and electronic equipment and devices
                  ("Third Party Equipment") owned by third parties ("Third
                  Parties") in specified portions of the Remaining Premises
                  pursuant to an agreement with Tenant, solely for the purpose
                  of permitting Tenant to connect the Third Party Equipment to
                  electrical power and the internet and provide electronic,
                  computer, data and telecommunication services to the Third
                  Party and to the Third Party Equipment ("Collocation
                  Services");

                  (b) The granting to Third Parties of a license, sublicense, or
                  other similar agreement whereby the Third Party has the right
                  to place its Third Party Equipment in designated locations
                  within the Remaining Premises for the sole purpose of
                  receiving Collocation Services; and

                  (c) The granting to Third Parties of the right to temporarily
                  enter portions of the Remaining Premises to operate, repair,
                  maintain, change, remove and/or replace their Third Party
                  Equipment."

         3.18     Section 21 of the Lease is further amended by adding the
following at the end:

                  "Notwithstanding the foregoing or anything else to the
                  contrary, if there is an Event of Bankruptcy as described
                  Article 23 (in Exhibit "F"), Tenant will still be deemed to
                  have been and to be in default if it fails to pay or perform
                  its obligations under this Lease as and when required even if
                  Landlord does not deliver or is prevented from delivering a
                  notice of such failure or a notice of default."

                                       13
<PAGE>

         3.19     Section 24.2 of the Lease is deleted and the following is
substituted:

                  "24.2 Entry By Landlord.

                  (a) Notwithstanding anything else to the contrary, Landlord
                  and its Affiliates will have the right to use any means
                  necessary to enter the Remaining Premises if Landlord believes
                  there is an emergency or that entry is necessary to prevent
                  damage or injury or protect health, safety or property, and in
                  such event Landlord will be required to give only such notice
                  (if any) that it in good faith believes is feasible under the
                  circumstances and need not wait to be accompanied by Tenant or
                  its employees or representatives (although these parties may
                  still accompany Landlord if they are available and wish to do
                  so). Otherwise Landlord and its Affiliates (and
                  representatives of the WSI Tenant or future tenants and their
                  respective Affiliates, if accompanied by a representative of
                  Landlord or its Affiliates or if otherwise approved for entry
                  by Tenant) will have the right to enter the Remaining Premises
                  only on at least twenty four (24) hours' prior notice. Tenant
                  may if it wishes provide a representative to accompany
                  Landlord or its Affiliates (and such other parties) during
                  such an entry, and in such cases those parties will comply
                  with legitimate security procedures of Tenant provided that
                  they do not unreasonably interfere with the exercise of
                  Landlord's rights under this Lease. Landlord will retain (or
                  be given by Tenant) keys to unlock all the doors to or within
                  the Remaining Premises, excluding doors to Tenant's vaults and
                  files. Entry to the Premises and the exercise of Landlord's
                  rights will not, under any circumstances, be deemed to be a
                  default, a forcible or unlawful entry into or a detainer of
                  the Remaining Premises or an eviction of Tenant from the
                  Remaining Premises or any portion thereof, nor will it subject
                  Landlord to any Liabilities or entitle Tenant to any
                  compensation, abatement of rent or other rights and remedies.
                  Tenant will not responsible for any Liabilities directly
                  resulting from the entry into the Remaining Premises by
                  Landlord or such other parties, except to the extent that such
                  Liabilities result from Tenant's default under this Lease or
                  the negligence or willful misconduct of Tenant or its
                  Affiliates."

         3.20     Sections 24.18(bx) and 24.18(bxx) of the Lease are amended to
replace "CMGI, Inc." with "Atlantic Investors LLC".

         3.21     Article 25 of the Lease is amended by adding the following at
the end:

                  "Without limiting the generality of the foregoing, Tenant will
                  be solely responsible for complying with all applicable Laws
                  in connection with the existing chillers and their
                  replacements and associated Systems and Equipment, and the
                  diesel fuel, the diesel holding tanks, the backup generators
                  and the rest of the Backup Power System."

         3.22 Section 23.2 in Exhibit "F" to the Lease is amended by adding the
following at the end "Any of the foregoing events sometimes may be called an
`Event of Bankruptcy' under this Lease."

                                       14
<PAGE>

         3.23     Rider #1 (Expansion Option) and Rider #3 (Additional Terms) to
the Lease are deleted.

         3.24     (a) On or before the Effective Date, Tenant will cause to be
irrevocably released and discharged pursuant to valid filed and recorded UCC-3's
and any other necessary documents, at no cost and without Liabilities to
Landlord, any and all liens, security interests, licenses, leases or other
encumbrances or exceptions to title: directly or indirectly held by CBT Finance;
or that encumber or attach to the Non-Removed Property, including, without
limitation, the Backup Power System. Tenant will indemnify and hold harmless
Landlord and its Affiliates from all Liabilities, direct or indirect, known or
unknown, foreseen or unforeseen, arising from Tenant's failure to perform these
obligations as and when required, and in addition to any other rights and
remedies of Landlord, if Tenant fails to so perform Landlord may perform any or
all of those obligations on Tenant's behalf at Tenant's cost and risk.

                  (b) Nothing in this Amendment or the rest of the Lease is
meant to imply that Tenant and Landlord are partners or co-venturers of any kind
or that they are agents of or owe fiduciary duties to each other, and Tenant and
its Affiliates will have no rights, interests, claims or remedies against the
WSI Tenant or Landlord or their respective Affiliates in connection with or as a
result of the WSI Lease except as otherwise specifically set forth in this
Amendment. During the term of the Lease Landlord will not amend the WSI Lease in
a manner that reduces the WSI Tenant's obligations to pay Operating Costs and/or
the WSI Payments so as to materially increase the Tenant's payments to Landlord
under the Lease without Tenant's prior written consent, which will not be
unreasonably withheld, conditioned or delayed, and which will be deemed granted
if Tenant fails to deliver a written notice reasonably withholding consent
within ten (10) days after Landlord delivers a written request for consent. All
obligations hereunder to indemnify, defend or hold harmless will survive the
termination of the Lease. Exhibits and Riders referred to herein that are
attached to this Amendment are incorporated into this Amendment. The terms of
Section 2 of this Amendment are true and correct and are incorporated into this
Amendment. This Amendment does not extend the term of the Lease.

                  (c) Although Tenant is vacating the WSI Space, Landlord will
not require Tenant to remove from the WSI Space the used furniture and equipment
described in Exhibit "B-1" hereto (the "Furniture"), which has nominal value. In
return, Tenant hereby irrevocably abandons the Furniture in favor of Landlord in
its "as is, where is" condition without any representation or warranty of any
kind whatsoever except as stated in the last sentence of this sub-section (c)
regarding title, and waives all further rights and interests therein, and agrees
that Landlord is free to remove, destroy, dispose of, use, sell, lease or convey
any or all of the Furniture in its sole discretion. Tenant represents and
warrants to Landlord that just before this abandonment it owned the Furniture
free and clear of all liens, leases, security interests and other rights and
claims, but Tenant makes no other representations and warranties regarding the
Furniture.

                  (d) In addition to and without limiting any other obligations
of Tenant or rights of Landlord hereunder: Tenant will cooperate in a
commercially reasonable manner with the exercise of the rights and the
performance of the obligations of Landlord and the WSI Tenant in connection with
the WSI Lease; and Landlord and the WSI Tenant each may freely exercise any or
all of its rights and remedies in connection with the WSI Lease in accordance
with the terms thereof, and this exercise, or any lack of exercise, will not
cause either of them to incur any

                                       15
<PAGE>

Liabilities to Tenant or Tenant's Affiliates, provided that they comply with the
specific terms of this Amendment.

                  (e) Landlord and Tenant each represents and warrants that it
has not dealt with or engaged any broker, agent, finder or similar party that is
due a fee from the other in connection with this Amendment.

                  (f) Landlord agrees (and will cause Farm Associates Limited
Partnership to agree) that ClearBlue Technologies, Inc. and ClearBlue Atlantic
LLC may distribute any common shares in Tenant that may be owned by them, and
that such distribution(s) and the acceptance of those shares by any recipient(s)
will not be deemed to be a default under the Subordination Agreement, dated as
of 9/11/2002, as amended, among Landlord, Farm Associates Limited Partnership,
Arthur Becker and Andrew Ruhan.

                  (g) Prior to this Amendment, Tenant had the obligation under
the Lease: to restore the entire Project to its condition as of the Rent
Commencement Date and repair all damage caused thereby; except for certain
Landlord obligations to repair and maintain the exterior of the Project, to
repair and maintain the interior and exterior of the entire Project and all
Systems and Equipment serving the Building, including, without limitation, the
elevators in the Building; and to deliver to and maintain for the benefit of
Landlord throughout the term of the Lease, as security for Tenant's obligations
and in certain instances as security for loans made to Landlord, a $4 Million
Letter of Credit pursuant to Section 24.17 of the Lease. As a result of this
Amendment and as more particularly described elsewhere in this Amendment, Tenant
has been relieved of many obligations under the Lease, and among other things
now is no longer obligated to: (i) restore any part of the Project to the
condition existing as of the Rent Commencement Date of the Lease (i.e.,
2/1/2000), and instead is obligated only to restore the Remaining Premises to
the condition existing as of the date of this Amendment; (ii) remove Alterations
existing as of the date of this Amendment, whether in the Remaining Premises or
the rest of the Project; (iii) repair the elevators, and instead has had its
repair and maintenance obligations significantly reduced; and (iv) provide the
Letter of Credit or any other security pursuant to Section 24.17 of the Lease.
As consideration for being relieved of these obligations as described in this
Amendment, Tenant has agreed to pay to Landlord the Initial Funds as provided in
this Amendment.

4.       No Other Changes.

         The Lease is in full force and effect, and except as set forth above
the Lease remains unchanged.

                                       16
<PAGE>

         IN WITNESS WHEREOF, intending to be legally bound, the parties have
executed this Amendment under seal as of the date first set forth above.

NAVISITE, INC., A DELAWARE            400 RIVER LIMITED PARTNERSHIP, A
CORPORATION                           MASSACHUSETTS LIMITED PARTNERSHIP

By  /s/ Jim Pluntze                   By: Niuna-400 River, Inc., a Massachusetts
    Name: Jim Pluntze                     corporation, general partner
    Title: CFO
    Authorized Signature

By:                                       By: /s/ Illegible
    Name:                                     Name:
    Title:                                    Title:
    Authorized Signature                      Authorized Signature


Although their agreement is not required by the terms of the Lease Guaranty, the
undersigned consent to this Amendment and agree that the Lease, as amended
hereby, continues to be guaranteed pursuant to the Lease Guaranty, which is in
full force and effect, and they specifically agree that they are bound by and
will comply with the terms of Section 3.2(g):

CLEARBLUE TECHNOLOGIES, INC.,         CLEARBLUE ATLANTIC LLC,
A DELAWARE CORPORATION                A DELAWARE LIMITED LIABILITY COMPANY

By: /s/ Arthur P. Becker              By: /s/ Arthur P. Becker
    Name: Arthur P. Becker                Name: Arthur P. Becker
    Title:                                Title:
    Authorized Signature                  Authorized Signature

                                      The undersigned also agrees that it is
                                      bound by and will comply with the terms of
                                      Section 3.2(g):

                                      CLEARBLUE FINANCE, INC.,
                                      A DELAWARE CORPORATION

                                      By: /s/ Arthur P. Becker

                                          Name: Arthur P. Becker
                                          Title:
                                          Authorized Signature

                                       17
<PAGE>


                                   EXHIBIT A-1

       REMAINING PREMISES, WSI SPACE, MDF/MER ROOMS, COMMON AREAS, PARKING

                                       18
<PAGE>

                                   EXHIBIT B-1

                                    FURNITURE

<PAGE>

                                   EXHIBIT D-1

                                    BASE RENT

     1. Notwithstanding anything to the contrary, and although Tenant has
     relinquished possession of the WSI Space and the Common Areas and Landlord
     may receive rent under the WSI Lease, as long as and only if Landlord has
     been deemed to have substantially completed the "Landlord's Work" in
     accordance with and as defined in the WSI Lease, for the first twenty-nine
     (29) months after the Rent Commencement Date under the WSI Lease Tenant
     will continue to pay the same base rent and the same Tenant's Percentage
     (i.e., 100%) of Taxes, Operating Costs and Landlord's insurance costs as it
     would have if it had continued to lease the entire Project (153,000 s.f. of
     rentable area) and not just the Remaining Premises (86,931 s.f. of rentable
     area). As a purely hypothetical example, assuming that the Rent
     Commencement Date under the WSI Lease is 12/1/2003, the annual base rent
     payable by Tenant for the period 12/1/2003 through 1/31/2006 will be
     $2,210,850 per year ($14.45 x 153,000 s.f.), and for the period 2/1/2006
     through 4/30/2006 it will be $2,287,350 per year ($14.95 x 153,000 s.f.),
     and for that entire 29-month period Tenant will pay 100% (and not merely
     56.8%) of the Operating Costs and Landlord's insurance costs as defined in
     the Lease, as amended by this Amendment.

     2. Starting on the first day of the 30th month after the Rent Commencement
     Date under the WSI Lease, and in addition to the amounts described below
     and any other amounts payable by Tenant as described in this Amendment
     (e.g., the amounts payable under Section 3.5 of this Amendment), during the
     remaining Lease term Tenant only will pay base rent at the rates set forth
     in the Lease for the Remaining Premises (86,931 s.f. of rentable area), and
     Tenant's Percentage of Taxes, Operating Costs and Landlord's insurance
     costs will be reduced to 56.8%; provided, however, that during the term of
     any Extension Option under the Lease, the base rent otherwise payable by
     Tenant during that term under the Lease will be increased by Sixty Cents
     ($0.60) per square foot of agreed rentable area in the Remaining Premises.

     3. Starting on the first day of the 30th month after the Rent Commencement
     Date under the WSI Lease, and in addition to the base rent described above
     and any other amounts payable by Tenant as described in this Amendment,
     during the remaining Lease term Tenant will pay to Landlord as additional
     base rent under the Lease: (a) the scheduled annual base rent per square
     foot under the Lease multiplied by the agreed rentable area of the WSI
     Space; less (b) the scheduled annual base rent per square foot under the
     WSI Lease multiplied by the agreed rentable area of the WSI Space. This
     additional base rent will be paid monthly in advance in the same manner as
     the rest of the base rent. As a purely hypothetical example, if the WSI
     Space contains 66,069 s.f. and the Rent Commencement Date of the WSI Lease
     is 12/31/2003, starting on the first day of the 30th month thereafter
     Tenant would pay $23,234 in additional base rent for that 30th month (i.e.,
     [66,069 s.f. x $14.95/12] - [66,069 s.f. x $10.73/12] = $22,234). However,
     notwithstanding the foregoing, if Tenant is not in default, Tenant will
     receive a credit and offset of $35,953 against its entire rent payments
     under the Lease for that 30th month.

<PAGE>

                                   EXHIBIT H-1

                               WSI RESERVED AREAS

<PAGE>

                                   EXHIBIT HH

                             RELOCATED DISH/ANTENNA