<PAGE>

                                                                   EXHIBIT 10.12

                                 THIRD AMENDMENT

         THIS THIRD AMENDMENT (the "Amendment") is made and entered into as of
the 27th day of October, 2003, by and between CA-GATEWAY OFFICE LIMITED
PARTNERSHIP, A DELAWARE LIMITED PARTNERSHIP ("Landlord"), and BACKWEB
TECHNOLOGIES INC., A DELAWARE CORPORATION ("Tenant").

                                    RECITALS

A.       Landlord (as successor by conversion to EOP-Gateway Office, L.L.C., a
         Delaware limited liability company, as successor in interest to Spieker
         Properties, L.P., a California limited partnership) and Tenant are
         parties to that certain office lease dated December 23, 1998 (the
         "Original Lease"), which Original Lease has been previously amended by
         that certain 1st Amendment to Lease - Expansion dated as of May 12,
         2000 (the "First Amendment") and by that certain 2nd Amendment to Lease
         - Expansion dated as of November 7, 2000 (the "Second Amendment", and
         together with the Original Lease and the First Amendment, collectively,
         the "Lease"). Pursuant to the Lease, Landlord has leased to Tenant
         space currently containing approximately 34,366 rentable square feet
         (the "Original Premises") described as Suite No. 300 on the third floor
         and Suite Nos. 500, 510 and 550 on the fifth floor, all of the building
         commonly known as Gateway Office IIB located at 2077 Gateway Place, San
         Jose, California (the "Building").

B.       Tenant desires to surrender a portion of the Premises to Landlord
         containing approximately 16,797 rentable square feet described as Suite
         No. 300 on the third floor of the Building as shown on EXHIBIT A-1
         hereto (the "Reduction Space") and that the Lease be appropriately
         amended, and Landlord is willing to accept such surrender on the
         following terms and conditions.

         NOW, THEREFORE, in consideration of the mutual covenants and agreements
herein contained and other good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, Landlord and Tenant agree as
follows:

I.       REDUCTION.

         A.       Tenant has vacated the Reduction Space in accordance with the
                  terms of the Lease on or prior to April 30, 2003, which is the
                  date immediately preceding the Reduction Effective Date
                  (defined in I.B. below). Landlord hereby acknowledges and
                  agrees that Tenant surrendered the Reduction Space in the
                  condition required by the terms and conditions of the Lease.

         B.       Effective as of May 1, 2003 (the "Reduction Effective Date"),
                  the Premises is decreased from 34,366 rentable square feet on
                  the third and fifth floor to 17,569 rentable square feet on
                  the fifth floor by the elimination of the Reduction Space. As
                  of the Reduction Effective Date, the Reduction Space shall be
                  deemed surrendered by Tenant to Landlord, the Lease shall be
                  deemed terminated with respect to the Reduction Space, and the
                  "Premises", as defined in the Lease, shall be deemed to mean
                  the Original Premises, less the Reduction Space; provided,
                  however, if Tenant's representations herein shall

<PAGE>

                  be materially false or misleading, Landlord shall have the
                  right to declare this Amendment null and void and to reinstate
                  the Lease with respect to the Reduction Space in addition to,
                  and not in lieu of, any other rights or remedies available to
                  Landlord.

         C.       Intentionally Omitted.

         D.       Notwithstanding anything in this Amendment to the contrary,
                  Tenant shall remain liable for all of its obligations as
                  Tenant under the Lease with respect to the Reduction Space, as
                  hereby amended, arising prior to the Reduction Effective Date.

II.      BASE RENT. Subject to the express terms hereof, upon full execution and
         delivery of this Amendment, and retroactively effective as of October
         1, 2002, the schedule of Base Rent contained in the Lease is deleted,
         and the following is substituted therefor:

<TABLE>
<CAPTION>
                                     ANNUAL RATE
MONTHS OF TERM OR                     PER SQUARE               MONTHLY
    PERIOD                               FOOT                 BASE RENT
---------------------              ----------------         ------------
<S>                                <C>                      <C>
10/1/2002 - 4/30/2003                   $18.00              $ 51,549.00*
 5/1/2003 - 9/30/2004                   $18.00              $26,353.50**
10/1/2004 - 1/31/2007               Determined as
 (Undetermined Rent                provided in this
      Period)                      Section II below
</TABLE>

*Based upon 34,366 rentable square feet, subject to abatement as described
below.

**Based upon 17,569 rentable square feet.

         Notwithstanding anything in the Lease to the contrary, Tenant shall be
         entitled to an abatement of (i) Base Rent in the amount of $25,195.50
         per month for the calendar months of October 2002 through and including
         April, 2003, and (ii) Tenant's Proportionate Share of Operating
         Expenses in the amount of (a) $15,979,00 per month for the calendar
         months of October 2002 through and including December, 2002 and (b)
         $15,630.31 per month for the calendar months of January 2003 through
         and including April, 2003. Such amount is equal to the Base Rent due on
         the Reduction Space at the rates stated in this Amendment for the Base
         Rent Abatement Period (as defined in the following sentence) and
         Tenant's Proportionate Share of Operating Expenses with respect to the
         Reduction Space for the Rent Abatement Period. The period of October 1,
         2002 through and including April 30, 2003 shall be sometimes be
         referred to herein as the "Rent Abatement Period". The total amount of
         Base Rent abated during the Rent Abatement Period shall equal
         $176,368.50 and the total amount of Tenant's Proportionate Share of
         Operating Expenses abated during the Rent Abatement Period shall equal
         $110,458.24 (collectively, the "Abated Rent"). During the Rent
         Abatement Period, only Base Rent and Tenant's Proportionate Share of
         Operating Expenses in the amounts stated above shall be abated, and all
         Additional Rent and other costs and charges specified in the Lease
         (including, without limitation, late fees and reconciliation of
         Operating Expenses) shall remain as due and payable pursuant to the
         provisions of the Lease, as hereby amended. Tenant has paid to Landlord
         Base Rent for October, 2002 through and including April, 2003 in a
         total amount equal to $543,760.88. Tenant

                                      -2-

<PAGE>

         has paid to Landlord Tenant's Proportionate Share of Operating Expenses
         for each for October, 2002 through and including April, 2003 in a total
         amount equal to $163,438.36. Subject to the terms of this Amendment
         (including Tenant's right to receive Abated Rent as provided above),
         Tenant's total obligation for the payment of Base Rent for the period
         commencing October, 2002 through and including April, 2003 is equal to
         $184,474.50 and Tenant's total obligation for the payment of Tenant's
         Proportionate Share of Operating Expenses for the period commencing
         October, 2002 through and including April, 2003 is equal to
         $115,501.36. Accordingly, Tenant's payments equal to $359,286.38 with
         respect to Base Rent and payments equal to $47,937.00 with respect to
         Tenant's Proportionate Share of Operating Expenses, for a total amount
         equal to $407,223.38 (the "Excess Payment"), are in excess of the
         amounts due for Base Rent and Tenant's Proportionate Share of Operating
         Expenses under the Lease, as amended hereby (subject to the terms of
         this paragraph).

         The parties agree that, subject to the terms hereof, so long as this
         Amendment is in full force and effect, Landlord shall apply 50% of the
         Excess Payment (i.e., $203,611.69) towards Tenant's obligation to pay
         to Landlord the next due and future installment(s) of Base Rent and
         Tenant's Proportionate Share of Operating Expenses in accordance with
         the terms of the Lease and this Amendment and 50% of the Excess Payment
         (i.e., $203,611.69) towards Tenant's obligation to pay to Landlord the
         Initial Reduction Fee (as defined in Section III.A below).

         All Base Rent and other sums due from Tenant shall be payable by Tenant
         in accordance with the terms of the Lease, as amended hereby.

         The Base Rent rate per rentable square foot of the Premises during the
         period commencing October 1, 2004 through and including January 31,
         2007 (the "Undetermined Rent Period") shall equal Landlord's Quoted
         Rate at the Airport (hereinafter defined) rate per rentable square foot
         for the Premises. Landlord shall advise Tenant of the applicable Base
         Rent rate for the Premises for the Undetermined Rent Period on or
         before September 1, 2004. Notwithstanding the foregoing and anything to
         the contrary contained in the Lease or this Amendment, IN NO EVENT
         SHALL THE BASE RENT FOR AND IN EFFECT DURING THE UNDETERMINED RENT
         PERIOD BE: (I) LESS THAN $2.75 PER RENTABLE SQUARE FOOT OF THE PREMISES
         PER MONTH ON A NNN BASIS, OR (II) MORE THAN THE LESSER OF (A) $3.25 PER
         RENTABLE SQUARE FOOT OF THE PREMISES PER MONTH ON A NNN BASIS, AND (B)
         LANDLORD'S QUOTED RATE AT THE AIRPORT PLUS $1.75 PER RENTABLE SQUARE
         FOOT OF THE PREMISES PER MONTH ON A NNN BASIS. For purposes hereof "NNN
         basis" shall mean Base Rent as calculated in a manner that excludes any
         Operating Expense component.

         For purposes of this Amendment, "Landlord's Quoted Rate at the Airport"
         shall mean the NNN rate quoted by Landlord or any affiliate of Landlord
         for similar space within the San Jose Airport Area (as defined herein)
         per rentable square foot on or about or otherwise covering the
         Undetermined Rent Period. The "San Jose Airport Area" shall mean the
         following projects so long as they are owned by Landlord or an
         affiliate of Landlord: (i) The Concourse, which currently includes the
         buildings located at 226 Airport Parkway, 224 Airport Parkway, 1731
         Technology Drive, 1735 Technology Drive, 1741 Technology Drive, 1745
         Technology Drive; (ii) Gateway

                                      -3-

<PAGE>

         Office Project, which currently includes the buildings located at 2001
         Gateway Place, 2033 Gateway Place, 2055 Gateway Place, 2077 Gateway
         Place, and 2099 Gateway Place; (iii) Metro Plaza, which currently
         includes the 3 office buildings located at 25 Metro Drive, 101 Metro
         Drive, and 181 Metro Drive; (iv) 1740 Technology Drive, San Jose, and
         (v) Skyport (Phase I), which currently includes the buildings located
         at 1700 Technology Drive, 1650 Technology Drive and 1600 Technology
         Drive.

III.     ADDITIONAL CONSIDERATION. As additional consideration for this
         Amendment, Tenant agrees to pay Landlord the following:

         A.       INITIAL REDUCTION FEE. Simultaneously with the Tenant's
                  execution of this Amendment, Tenant shall pay to Landlord, by
                  cashier's or certified check or by wire transfer of
                  immediately available funds to an account designated by
                  Landlord, the sum of $2,300,000.00 (the "Initial Reduction
                  Fee").

                  Notwithstanding anything to the contrary contained in the
                  Lease, Landlord and Tenant hereby acknowledge and agree that
                  Landlord currently is holding the cash sum of $1,203,971.00 as
                  a portion of the security deposit (the "Cash Security
                  Deposit") required pursuant to the terms of Section 19 of the
                  Original Lease. Landlord and Tenant acknowledge and agree that
                  upon the full and proper execution of this Amendment by
                  Landlord and Tenant (i) Landlord shall retain the Cash
                  Security Deposit in its entirety and apply such amount toward
                  Tenant's obligation to pay to Landlord the Initial Reduction
                  Fee; (ii) Landlord shall retain the Excess Payment in its
                  entirety and apply such amount toward Tenant's obligation to
                  pay to Landlord Base Rent and Tenant's Proportionate Share of
                  Operating Expenses and the Initial Reduction Fee in accordance
                  with Section II if this Amendment; and (iii) Tenant shall be
                  deemed to have assigned, quitclaimed and surrendered to
                  Landlord, its successors and assigns, all of Tenant's right,
                  title and interest in and to the Cash Security Deposit and the
                  Excess Payment and further shall release any and all claims to
                  the Cash Security Deposit and the Excess Payment.

         B.       ADDITIONAL REDUCTION FEE. Concurrently with Tenant's execution
                  and delivery to Landlord of this Amendment, Tenant shall
                  execute and deliver to Landlord an original promissory note,
                  in the form attached hereto as EXHIBIT E (the "Additional
                  Reduction Fee Promissory Note"), the amount of which
                  Promissory Note shall be an additional reduction fee (the
                  "Additional Reduction Fee).

IV.      TENANT'S PROPORTIONATE SHARE; OPERATING EXPENSES RECONCILIATION.

         A.       PROPORTIONATE SHARE. For the period commencing on the
                  Reduction Effective Date and ending on January 31, 2007 (the
                  "Termination Date"), Tenant's Proportionate Share is decreased
                  from 45.51% to 23.26%. Notwithstanding anything in this
                  Amendment to the contrary, Tenant shall remain liable for all
                  year-end adjustments with respect to Tenant's Proportionate
                  Share of Operating Expenses applicable to the Reduction Space
                  for that portion of the calendar year preceding the Reduction
                  Effective Date. Such adjustments

                                      -4-

<PAGE>

                  shall be paid at the time, in the manner and otherwise in
                  accordance with the terms of the Lease, unless otherwise
                  specified herein.

         B.       OPERATING EXPENSES RECONCILIATION. Retroactively effective as
                  of October 1, 2002, the 4th and 5th sentences of Paragraph 7.C
                  of the Original Lease is hereby deleted in its entirety and
                  shall be replaced by the following: "If this Lease has been
                  terminated or the Term hereof has expired prior to the date of
                  such statement, then the Operating Expense Adjustment, if any,
                  shall be paid by Tenant to Landlord within twenty (20) days
                  after the date of delivery of the statement.". The parties
                  hereto acknowledge and agree that in further consideration for
                  Landlord's willingness to enter into this Amendment, Tenant
                  shall waive its right to any refunds during the Term based
                  upon any Operating Expense Adjustment.

V.       REPRESENTATIONS. Each party represents to the other that it has full
         power and authority to execute this Amendment. Tenant represents that
         it has not made any assignment, sublease, transfer, conveyance of the
         Lease or any interest therein or in the Reduction Space other than
         those explicitly recited herein and further represents that there is
         not and will not hereafter be any claim, demand, obligation, liability,
         action or cause of action by any other party respecting, relating to or
         arising out of the Reduction Space and relating to or arising during
         Tenant's leasehold interest in the Reduction Space, and Tenant agrees
         to indemnify and hold harmless Landlord and the Landlord Related
         Parties (as defined in the "Miscellaneous" Section below) from all
         liabilities, expenses, claims, demands, judgments, damages or costs
         arising from any of the same, including without limitation, attorneys'
         fees. Tenant acknowledges that Landlord will be relying on this
         Amendment in entering into leases for the Reduction Space with other
         parties.

VI.      OTHER PERTINENT PROVISIONS. Landlord and Tenant agree that, effective
         as of the date of this Amendment (unless different effective dates are
         specifically referenced in this Section), the Lease shall be amended in
         the following additional respects:

         A.       DELETED PROVISIONS. The following provisions shall be deleted
                  in their entirety and are null and void and of no further
                  force or effect: Exhibit C to the Original Lease (Tenant
                  Improvements); the second sentence of the first full paragraph
                  of Paragraph 8 of the First Amendment (Tenant Improvements);
                  Exhibit 1 to the First Amendment (Tenant Improvements); and
                  the second sentence of Paragraph 8 of the Second Amendment
                  (Tenant Improvements).

         B.       LANDLORD'S NOTICE ADDRESS. Landlord's Notice Address defined
                  in the Basic Lease Information of the Original Lease is hereby
                  deleted in its entirety and the following shall be substituted
                  therefor:

                                      -5-

<PAGE>

Landlord:                                With a copy to:

CA-Gateway Office Limited Partnership    Equity Office Properties Trust
c/o Equity Office Properties Trust       Two North Riverside Plaza
1740 Technology Drive, Suite 150         Suite 2100
San Jose, California 95110               Chicago, Illinois 60606
Attention:  Property Manager             Attention: Regional Counsel - San Jose
                                         Region"


         C.       LANDLORD'S REMITTANCE ADDRESS. Landlord's Remittance Address
                  defined the Basic Lease Information of the Original Lease is
                  hereby deleted in its entirety and the following shall be
                  substituted therefor: "CA-Gateway Office Limited Partnership,
                  P.O. Box 45587, Dept. 13472, San Francisco, California
                  94145-0587".

                  Rent and all other sums that Tenant is required to pay
                  Landlord are payable to the order of EQUITY OFFICE PROPERTIES.

         D.       UTILITY DEREGULATION. Notwithstanding anything to the contrary
                  contained in the Lease, as amended hereby, if and to the
                  extent permitted by applicable law, Landlord shall be entitled
                  to receive a fee for the service provided by Landlord in
                  connection with the selection of utility companies and the
                  negotiation and administration of contracts for electricity,
                  provided that such fee shall not exceed 50% of any savings
                  obtained by Landlord.

         E.       RELOCATION. Landlord, at Tenant's expense, at any time during
                  the Term, may relocate Tenant from the Premises to the space
                  as of the date hereof known as Suite 300, a depiction thereof
                  is attached hereto as EXHIBIT A-2 (the "Relocation Space") in
                  the Building upon 90 days' prior written notice to Tenant. The
                  Relocation Space consists of approximately 16,797 rentable
                  square feet. From and after the date of the relocation,
                  "Premises" shall refer to the Relocation Space and the Base
                  Rent and Tenant's Proportionate Share shall be adjusted based
                  on the rentable square footage of the Relocation Space. Tenant
                  shall execute such documents as may be required by Landlord to
                  reflect such relocation. The Relocation Space must contain
                  similar finishes as the Premises, and approximately the same
                  Rentable Square Footage as the Premises as of the date Tenant
                  receives Landlord's notice of relocation.

         F.       LETTER OF CREDIT/SECURITY DEPOSIT. Concurrent with Tenant's
                  execution and delivery of this Amendment, Tenant shall deliver
                  to Landlord an amount equal to $200,000.00 (the "Additional
                  Security Deposit") as an addition to and part of the Security
                  Deposit held by Landlord pursuant to Section 19 of the
                  Original Lease. The Security Deposit shall be held by Landlord
                  without liability for interest (unless required by
                  Regulations) as security for the performance of Tenant's
                  obligations. The parties hereto acknowledge and agree that:
                  (i) Landlord currently holds irrevocable letter of credit
                  issued by Bank Leumi USA as number S10038498 in an amount
                  equal to $300,000.00 (the "Existing LC"), and (ii) the Cash
                  Security Deposit currently held by Landlord shall be applied
                  to Tenant's obligation to pay to Landlord a portion

                                      -6-

<PAGE>

                  of the Initial Reduction Fee (as defined in Section III of
                  this Amendment). The parties hereto intend to increase the
                  remaining amount of the Security Deposit from $300,000.00 by
                  an amount equal to the Additional Security Deposit to a total
                  amount of $500,000.00.

                  The Additional Security Deposit may be in the form of cash or
                  an irrevocable letter of credit. In the event the Additional
                  Security Deposit is provided in the form of an irrevocable
                  letter of credit, Tenant may amend the Existing LC to increase
                  the amount thereof to a total amount equal to $500,000.00 and
                  to make other reasonable modifications as required by Landlord
                  (including, without limitation, amending the Existing LC to
                  reflect Landlord as the beneficiary thereof) or,
                  alternatively, Tenant may provide a new letter of credit in a
                  total amount equal to $500,000.00 (the "New LC"). In the event
                  that Tenant provides the New LC, such New LC shall: (a) be in
                  the total amount of $500,000.00; (b) be issued on the form
                  attached hereto as EXHIBIT D; (c) name Landlord as its
                  beneficiary; and (d) be drawn on an FDIC insured financial
                  institution satisfactory to the Landlord. The New LC (and any
                  renewals or replacements thereof) shall be for a term of not
                  less than 1 year and shall have a final expiration date no
                  less than 60 days following the expiration of the Term of the
                  Lease. The term "Letter of Credit" as used herein shall mean
                  either the New LC or the amended Existing LC, as the case may
                  be.

                  Tenant agrees that it shall from time to time, as necessary,
                  whether as a result of a draw on the Letter of Credit by
                  Landlord pursuant to the terms hereof or as a result of the
                  expiration of the Letter of Credit then in effect, renew or
                  replace the original and any subsequent Letter of Credit so
                  that a Letter of Credit, in the amount required hereunder, is
                  in effect until a date which is at least 60 days after the
                  Termination Date of the Lease. If Tenant fails to furnish such
                  renewal or replacement at least 60 days prior to the stated
                  expiration date of the Letter of Credit then held by Landlord,
                  Landlord may draw upon such Letter of Credit and hold the
                  proceeds thereof (and such proceeds need not be segregated) as
                  a Security Deposit pursuant to the terms of Section 19 of the
                  Original Lease. Any renewal or replacement of the original or
                  any subsequent Letter of Credit shall meet the requirements
                  for the original Letter of Credit as set forth above, except
                  that such replacement or renewal shall be issued by an FDIC
                  insured financial institution satisfactory to the Landlord at
                  the time of the issuance thereof.

                  If Landlord draws on the Letter of Credit as permitted in the
                  Lease, as amended hereby, or as permitted in the Letter of
                  Credit, then, upon demand of Landlord, Tenant shall restore
                  the amount available under the Letter of Credit to its
                  original amount of $500,000.00 by providing Landlord with an
                  amendment to the Letter of Credit evidencing that the amount
                  available under the Letter of Credit has been restored to its
                  original amount. In the alternative, Tenant may provide
                  Landlord with cash, to be held by Landlord in accordance with
                  the Lease, as amended hereby, equal to the restoration amount
                  required under the Letter of Credit.

                                      -7-

<PAGE>

         G.       WARRANT. As additional consideration for Landlord's
                  willingness to reduce the Premises, concurrent with Tenant's
                  execution and delivery of this Amendment, Tenant shall deliver
                  to Landlord a warrant agreement in the form attached hereto as
                  EXHIBIT F (the "Warrant") to purchase 200,000 shares of
                  ordinary shares (the "Ordinary Shares") in Guarantor (as
                  defined below) at $ 0.66 per share, which Warrant shall be
                  exercisable during the time period commencing on the date of
                  this Amendment through and including the day preceding the
                  seventh annual anniversary thereof.

         H.       GUARANTEES. Concurrent with Tenant's execution and delivery of
                  this Amendment, Tenant shall cause BackWeb Technologies, LTD.,
                  an Israeli corporation ("Guarantor") to execute and deliver to
                  Landlord two guarantees, one document in the form attached
                  hereto as EXHIBIT B (the "Guaranty of Lease") which guarantees
                  Tenant's performance under the Lease, and one document in the
                  form attached hereto as EXHIBIT C (the "Guaranty of Note")
                  which guarantees Tenant's performance as "Maker" under the
                  Promissory Note.

VII.     MISCELLANEOUS.

         A.       This Amendment sets forth the entire agreement between the
                  parties with respect to the matters set forth herein. There
                  have been no additional oral or written representations or
                  agreements. Under no circumstances shall Tenant be entitled to
                  any Rent abatement, improvement allowance, leasehold
                  improvements, or other work to the Premises, or any similar
                  economic incentives that may have been provided Tenant in
                  connection with entering into the Lease, unless specifically
                  set forth in this Amendment. This Amendment shall not be
                  relied upon by any other party, individual, corporation,
                  partnership or entity as a basis for reducing its lease
                  obligations with Landlord or for any other purpose.

         B.       Except as herein modified or amended, the provisions,
                  conditions and terms of the Lease shall remain unchanged and
                  in full force and effect.

         C.       In the case of any inconsistency between the provisions of the
                  Lease and this Amendment, the provisions of this Amendment
                  shall govern and control.

         D.       Submission of this Amendment by Landlord is not an offer to
                  enter into this Amendment but rather is a solicitation for
                  such an offer by Tenant. Landlord shall not be bound by this
                  Amendment until Landlord has executed and delivered the same
                  to Tenant.

         E.       The capitalized terms used in this Amendment shall have the
                  same definitions as set forth in the Lease to the extent that
                  such capitalized terms are defined therein and not redefined
                  in this Amendment.

         F.       Tenant hereby represents to Landlord that Tenant has dealt
                  with no broker in connection with this Amendment. Tenant
                  agrees to indemnify and hold Landlord, its members,
                  principals, beneficiaries, partners, officers, directors,

                                      -8-

<PAGE>

                  employees, mortgagee(s) and agents, and the respective
                  principals and members of any such agents harmless from all
                  claims of any brokers claiming to have represented Tenant in
                  connection with this Amendment. Landlord hereby represents to
                  Tenant that Landlord has dealt with no broker in connection
                  with this Amendment. Landlord agrees to indemnify and hold
                  Tenant, its members, principals, beneficiaries, partners,
                  officers, directors, employees, and agents, and the respective
                  principals and members of any such agents harmless from all
                  claims of any brokers claiming to have represented Landlord in
                  connection with this Amendment. Equity Office Properties
                  Management Corp. ("EOPMC") is an affiliate of Landlord and
                  represents only the Landlord in this transaction. Any
                  assistance rendered by any agent or employee of EOPMC in
                  connection with this Amendment or any subsequent amendment or
                  modification to the Lease has been or will be made as an
                  accommodation to Tenant solely in furtherance of consummating
                  the transaction on behalf of Landlord, and not as agent for
                  Tenant.

         G.       Each signatory of this Amendment represents hereby that he or
                  she has the authority in his or her representative capacity to
                  execute and deliver the same on behalf of the party hereto for
                  which such signatory is acting.

         H.       Except to the extent required by any applicable Securities and
                  Exchange Commission requirements, or any applicable Federal or
                  State securities laws (collectively, the "Securities Laws"),
                  Tenant agrees that neither Tenant nor its agents or any other
                  parties acting on behalf of Tenant shall disclose any matters
                  set forth in this Amendment or disseminate or distribute any
                  information concerning the terms, details or conditions hereof
                  to any person, firm or entity without obtaining the express
                  written consent of Landlord. Tenant is required by Securities
                  Laws to disclose certain information contained in this
                  Amendment and, in accordance with such requirement, Tenant (or
                  such other persons to whom such disclosure request or
                  requirement applies) shall disclose or otherwise furnish only
                  the information legally required to be disclosed, as advised
                  by legal counsel, and such disclosure shall be made only to
                  the necessary and appropriate governmental entities. Landlord
                  acknowledges and agrees that if this Amendment is a "material
                  contract" for purposes of Securities Laws, Tenant shall be
                  required to file this Amendment with the Securities and
                  Exchange Commission as part of its regulatory filings as a
                  material contract.

                       [SIGNATURES ARE ON FOLLOWING PAGE]

                                      -9-

<PAGE>

IN WITNESS WHEREOF, Landlord and Tenant have duly executed this Amendment as of
the day and year first above written.

                           LANDLORD:

                           CA-GATEWAY OFFICE LIMITED PARTNERSHIP, A
                           DELAWARE LIMITED PARTNERSHIP

                           By: EOM GP, L.L.C., a Delaware limited liability
                               company, its general partner

                               By: Equity Office Management, L.L.C., a
                                   Delaware limited liability company, its non-
                                   member manager

                                   By: /s/  JOHN W. PETERSEN
                                       ---------------------

                                       Name: John W. Petersen

                                       Title: Regional Senior Vice President

                           TENANT:

                           BACKWEB TECHNOLOGIES INC., A DELAWARE
                           CORPORATION

                           By: /s/ MICHAEL A. MORGAN
                               --------------------

                           Name: Michael Morgan

                           Title:      CFO

                                      -10-

<PAGE>

                                   EXHIBIT A-1

                     OUTLINE AND LOCATION OF REDUCTION SPACE
                                   [schematic]

                                      -11-

<PAGE>

                                   EXHIBIT A-2

                    OUTLINE AND LOCATION OF RELOCATION SPACE
                                   [schematic]

                                      -12-

<PAGE>

                                    EXHIBIT B

                                FORM OF GUARANTY

                                GUARANTY OF LEASE

         CA-GATEWAY OFFICE LIMITED PARTNERSHIP, A DELAWARE LIMITED PARTNERSHIP
("Landlord") has leased certain real property to BACKWEB TECHNOLOGIES INC., A
DELAWARE CORPORATION, as tenant ("Tenant"), pursuant to that certain office
lease by and between Landlord and Tenant and dated December 23, 1998 (the
"Original Lease"), which Original Lease has been previously amended by that
certain 1st Amendment to Lease - Expansion dated as of May 12, 2000, and by that
certain 2nd Amendment to Lease - Expansion dated as of November 7, 2000, and is
further amended by that certain Third Amendment dated October 27, 2003 (the
"Third Amendment", and together with the 1st Amendment to Lease - Expansion and
the 2nd Amendment to Lease - Expansion, collectively, the "Lease"). FOR VALUE
RECEIVED and in consideration for and as an inducement to Landlord to enter into
the Third Amendment, which Third Amendment modifies the Premises and the Base
Rent (as each is defined in the Lease), the undersigned, BACKWEB TECHNOLOGIES
LTD, AN ISRAELI CORPORATION ("Guarantor") does hereby unconditionally and
irrevocably guarantee to Landlord the punctual payment of all Rent (as such term
is defined in the Lease) payable by Tenant under the Lease throughout the term
of the Lease and any and all renewals and extensions thereof in accordance with
and subject to the provisions of the Lease, and the full performance and
observance of all other terms, covenants, conditions and agreements therein
provided to be performed and observed by Tenant under the terms of the Lease,
for which the undersigned shall be jointly and severally liable with Tenant. If
any default on the part of Tenant shall occur under the Lease, the undersigned
does hereby covenant and agree to pay to Landlord upon-demand in each and every
instance such sum or sums of money and to perform each and every covenant,
condition and agreement under the Lease as Tenant is and shall become liable for
or obligated to pay or perform under the Lease, together with the costs
reasonably incurred by Landlord in connection therewith, including, without
limitation, reasonable attorneys' fees. Such payments of Rent and other sums
shall be made monthly or at such other intervals as the same shall or may become
payable under the Lease, including any accelerations thereof, all without
requiring any notice from Landlord (other than any notice required by the Lease)
of such non-payment or non performance, all of which the undersigned hereby
expressly waives.

         The maintenance of any action or proceeding by Landlord to recover any
sum or sums that may be or become due under the Lease and to secure the
performance of any of the other terms, covenants and conditions of the Lease
shall not preclude Landlord from thereafter instituting and maintaining
subsequent actions or proceedings for any subsequent default or defaults of
Tenant under the Lease. The undersigned does hereby consent that without
affecting the liability of the undersigned under this Guaranty and without
notice to the undersigned, time may be given by Landlord to Tenant for payment
of Rent and such other sums and performance of said other terms, covenants and
conditions, or any of them, and such time extended and indulgence granted, from
time to time, or Tenant may be dispossessed or Landlord may avail itself of or
exercise any or all of the rights and remedies against Tenant provided by law or
by the Lease, and may proceed either against Tenant alone or jointly against
Tenant and the undersigned or against the undersigned alone without first
prosecuting or exhausting any remedy or claim against Tenant. The undersigned
does

                                      -13-

<PAGE>

hereby further consent to any subsequent change, modification or amendment of
the Lease in any of its terms, covenants or conditions, or in the Rent payable
thereunder, or in the premises demised thereby, or in the term thereof, and to
any assignment or assignments of the Lease, and to any subletting or sublettings
of the premises demised by the Lease, and to any renewals or extensions thereof,
all of which may be made without notice to or consent of the undersigned and
without in any manner releasing or relieving the undersigned from liability
under this Guaranty.

         The undersigned does hereby agree that the bankruptcy of Tenant shall
have no effect on the obligations of the undersigned hereunder. The undersigned
does hereby further agree that in respect of any payments made by the
undersigned hereunder, the undersigned shall not have any rights based on
suretyship, subrogation or otherwise to stand in the place of Landlord so as to
compete with Landlord as a creditor of Tenant, unless and until all claims of
Landlord under the Lease shall have been fully paid and satisfied.

         The undersigned hereby waives and agrees not to assert: (a) any right
to require Landlord to proceed against Tenant, or any other guarantor or person
or to pursue any other security or remedy before proceeding against the
undersigned; (b) any defense based on the validity or enforceability of the
Lease; (c) any right or defense that may arise by reason of the incapacity, lack
of authority, death or disability of Tenant or any other person; and (d) any
right or defense arising by reason of the absence, impairment, modification,
limitation, destruction or cessation (in bankruptcy, by an election of remedies,
or otherwise) of the liability of Tenant of the subrogation rights of the
undersigned or of the right of the undersigned to proceed against Tenant for
reimbursement. The undersigned waives any right, statutory, or otherwise, for
itself to require or for Tenant to require Landlord to apply rents received
toward the obligations of the undersigned under this Guaranty, or to otherwise
prioritize the receipt of rents as against the obligations of the undersigned
under this Guaranty. The undersigned hereby waives and agrees not to assert (x)
any right or defense based on the absence of any or all presentments, demands
(including demands for performance), notices (including notices of any adverse
change in the financial status of Tenant, notices of any other facts which
increase the risk to the undersigned, notices of non-performance and notices of
acceptance of this Guaranty) and protests of each and every kind; (y) the
defense of any statute of limitations in any action under or related to this
Guaranty or the Lease; and (z) any right or defense based on a lack of diligence
or failure or delay by Landlord in enforcing its rights under this Guaranty or
the Lease. The undersigned hereby waives and agrees not to assert or take
advantage of any right to (i) exoneration if Landlord's actions shall impair any
security or collateral of the undersigned; (ii) any security or collateral held
by Landlord; (iii) require Landlord to proceed against or exhaust any security
or collateral before proceeding against the undersigned; and (iv) require
Landlord to pursue any right or remedy for the benefit of the undersigned.
Without limiting the generality of any of the covenants and agreements of the
undersigned set forth in this Guaranty, the undersigned hereby waives any and
all benefits of the provisions of Sections 2809, 2810, 2819, 2822, 2845, 2848,
2849 and 2850 of the California Civil Code and any similar or analogous statutes
of California or any jurisdiction.

         Until all the Tenant's obligations under the Lease are fully performed,
the undersigned (a) shall have no right of subrogation or reimbursement against
the Tenant by reason of any payments or acts of performance by the undersigned
under this Guaranty, (b) subordinates any liability or indebtedness of the
Tenant now or hereafter held by the

                                      -14-

<PAGE>

undersigned to the obligations of the Tenant under, arising out of or related to
the Lease or Tenant's use of the Premises; and (c) acknowledges that the actions
of Landlord may affect or eliminate any rights of subrogation or reimbursement
of the undersigned as against Tenant without any liability or recourse against
Landlord.

         Neither this Guaranty nor any of the provisions hereof can be modified,
waived or terminated, except by a written instrument signed by Landlord. The
provisions of this Guaranty shall apply to, bind and inure to the benefit of the
undersigned and Landlord and their respective heirs, legal representatives,
successors and assigns. As used herein, the term "Tenant" means the Tenant
specifically named in the Lease and also any assignee or subtenant of said Lease
and any successor to the interests of said Tenant, assignee or sublessee of such
Lease or any part thereof, whether by assignment, sublease or otherwise
including, without limitation, any trustee in bankruptcy and any bankruptcy
estate of Tenant, Tenant's assignee or sublessee. The undersigned, if there be
more than one, shall be jointly and severally liable hereunder, and for purposes
of such several liability the word "undersigned" wherever used herein shall be
construed to refer to each of the undersigned parties separately, all in the
same manner and with the same effect as if each of them had signed separate
instruments, and this Guaranty shall not be revoked or impaired as to any of
such parties by the death of another party or by revocation or release of any
obligations hereunder of any other party.

         If Landlord should retain counsel and/or institute any suit against
Guarantor to enforce this Guaranty or any covenants or obligations hereunder,
then Guarantor shall pay to Landlord, upon demand, all reasonable attorneys'
fees, costs and expenses, including, without limitation, court costs, filing
fees, recording costs, and all other costs and expenses incurred in connection
therewith (all of which are referred to herein as "Enforcement Costs"), in
addition to all other amounts due hereunder. This Guaranty shall be governed by
and construed in accordance with the internal laws of the state where the
premises demised by the Lease are located. For the purpose solely of litigating
any dispute under this Guaranty, the undersigned submits to the jurisdiction of
the courts of the United States of America and said state. The undersigned
hereby waives any right to trial by jury and further waives and agrees not to
assert or take advantage of any defense based on the claim that any arbitration
decision binding upon Landlord or Tenant is not binding on the undersigned.

         Any notice or other communication to be given to Landlord or the
undersigned hereunder shall be in writing and sent in accordance with the notice
provisions of the Lease. Notices to Landlord shall be delivered to Landlord's
address set forth in the Lease. Notices to the undersigned shall be addressed as
follows: 2077 Gateway Place, Suite 500, San Jose, CA 95110, Attention: Finance
Department. In the event Guarantor's notice address as set forth above changes,
Guarantor agrees to provide written notice to Landlord of such change in
address.

         This Guaranty shall be construed and enforced in accordance with the
laws of the State of California. Any legal action or proceeding with respect to
this Guaranty and any action for enforcement of any judgment in respect thereof
may be brought in the courts of California or the United States of America for
the Northern District of California and by execution and delivery of this
guaranty, Guarantor hereby accepts unconditionally the non-exclusive
jurisdiction of the aforementioned courts and their respective appellate courts.
Guarantor hereby irrevocably consents to the service of process out of any of
these

                                      -15-

<PAGE>

aforementioned courts in any such action or proceeding by the mailing of copies
thereof by a reputable international courier to Guarantor at the address
provided in Paragraph 1. Guarantor irrevocably waives any objection which it may
now or hereafter have to the laying of venue in any of the courts referred to
above arising out of or in connection any action or proceeding on this Guaranty
brought in any of the courts referred to above and further irrevocably waives
and agrees not to plead or claim in any such court that any such action or
proceeding has been brought in an inconvenient forum.

                         [SIGNATURES ON FOLLOWING PAGE]

                                      -16-

<PAGE>

IN WITNESS WHEREOF, the undersigned has executed this Guaranty as of the date of
the ______ day of _____________, 2003.


                                         GUARANTOR:

                                         BACKWEB TECHNOLOGIES, LTD, AN ISRAELI
                                         CORPORATION

                                         By: ___________________________________

                                         Name: _________________________________

                                         Title:_________________________________

                                         By: ___________________________________

                                         Name: _________________________________

                                         Title: ________________________________

                                      -17-

<PAGE>

                            LANDLORD ACKNOWLEDGMENTS

STATE OF ____________)
COUNTY OF ___________)  ss:

         I, the undersigned, a Notary Public, in and for the County and State
aforesaid, do hereby certify that ____________________________, personally known
to me to be the __________ President of Equity Office Properties Trust, a
Maryland real estate investment trust, and personally known to me to be the same
person whose name is subscribed to the foregoing instrument, appeared before me
this day in person and acknowledged that as such officer of said entity being
authorized so to do, (s)he executed the foregoing instrument on behalf of said
entity, by subscribing the name of such entity by himself/herself as such
officer, as a free and voluntary act, and as the free and voluntary act and deed
of said entity, for the uses and purposes therein set forth.

GIVEN under my hand and official seal this ___ day of ___________, 20__.

                                                      __________________________
                                                         Notary Public

My Commission Expires: __________

                             TENANT ACKNOWLEDGMENTS
                                   INDIVIDUAL

STATE OF ____________)
COUNTY OF ___________)  ss:

         I, the undersigned, as Notary Public in and for the County and State
aforesaid, do hereby certify that ____________________________, personally known
to me to be the same person whose name is subscribed to the foregoing
instrument, appeared before me this day in person and acknowledged that (s)he
signed the said instrument as a free and voluntary act for the uses and purposes
therein set forth.

         GIVEN under my hand and official seal this ___ day of _________, 20__.

                                                     ___________________________
                                                         Notary Public

My Commission Expires: __________

                                      -18-

<PAGE>

                                   CORPORATION

STATE OF ____________)
COUNTY OF ___________)  ss:

         On this the ___ day of ____________, 20__, before me a Notary Public
duly authorized in and for the said County in the State aforesaid to take
acknowledgments personally appeared __________________________ known to me to be
____________ President of ________________________, one of the parties described
in the foregoing instrument, and acknowledged that as such officer, being
authorized so to do, (s)he executed the foregoing instrument on behalf of said
corporation by subscribing the name of such corporation by himself/herself as
such officer and caused the corporate seal of said corporation to be affixed
thereto, as a free and voluntary act, and as the free and voluntary act of said
corporation, for the uses and purposes therein set forth.

         IN WITNESS WHEREOF, I hereunto set my hand and official seal.

                                                      __________________________
                                                         Notary Public

My Commission Expires: __________

                                   PARTNERSHIP

STATE OF ____________)
COUNTY OF ___________)  ss:

         On this the ___ day of ________________, 20__, before me a Notary
Public duly authorized in and for the said County in the State aforesaid to take
acknowledgments personally appeared _____________ known to me to be a general
partner of a partnership known as _______________________________, one of the
parties described in the foregoing instrument, and acknowledged that being
authorized so to do, (s)he executed the foregoing instrument on behalf of said
partnership by subscribing the name of said partnership by himself/herself, as a
free and voluntary act, and as the free and voluntary act of said partnership,
for the uses and purposes therein set forth.

         IN WITNESS WHEREOF, I hereunto set my hand and official seal.

        `                                             __________________________
                                                         Notary Public

My Commission Expires: __________

                                      -19-

<PAGE>

                                    EXHIBIT C

                                FORM OF GUARANTY

                                GUARANTY OF NOTE

         FOR VALUE RECEIVED and in consideration for and as an inducement to
CA-GATEWAY OFFICE LIMITED PARTNERSHIP, A DELAWARE LIMITED PARTNERSHIP ("Payee")
to enter in to the Third Amendment (as defined below) respecting certain real
property leased to BACKWEB TECHNOLOGIES INC., A DELAWARE CORPORATION, as tenant
("Maker"), which is leased by Maker pursuant to that certain office lease by and
between Payee (as "Landlord") and Maker (as "Tenant") and dated December 23,
1998 (the "Original Lease"), which Original Lease has been previously amended by
that certain 1st Amendment to Lease - Expansion dated as of May 12, 2000, and by
that certain 2nd Amendment to Lease - Expansion dated as of November 7, 2000,
and further amended by that certain Third Amendment dated October 27, 2003 (the
"Third Amendment", and, together with the 1st Amendment to Lease - Expansion and
the 2nd Amendment to Lease - Expansion, collectively, the "Lease"), the
undersigned, BACKWEB TECHNOLOGIES LTD, AN ISRAELI CORPORATION ("Guarantor") does
hereby unconditionally and irrevocably guarantee to Payee the punctual payment
payable by Maker under the that certain Promissory Note of even date herewith
(the "Note"), including, without limitation, the Additional Reduction Fee (as
defined in the Third Amendment and in the Note), throughout the term of the
Lease and the Note, as the case may be, for which the undersigned shall be
jointly and severally liable with Maker. If any default on the part of Maker
shall occur under the Note, the undersigned does hereby covenant and agree to
pay to Payee upon demand in each and every instance such sum or sums of money
and to perform each and every covenant, condition and agreement under the Note
as Maker is and shall become liable for or obligated to pay or perform under the
Note, together with the costs reasonably incurred by Payee in connection
therewith, including, without limitation, reasonable attorneys' fees. Such
payments of the Principal Amount and other sums shall be made monthly or at such
other intervals as the same shall or may become payable under the Note, all
without requiring any notice from Payee (other than any notice required by the
Note, if any) of such non-payment or non performance, all of which the
undersigned hereby expressly waives.

         The maintenance of any action or proceeding by Payee to recover any sum
or sums that may be or become due under the Note and to secure the performance
of any of the other terms, covenants and conditions of the Note shall not
preclude Payee from thereafter instituting and maintaining subsequent actions or
proceedings for any subsequent default or defaults of Maker under the Note. The
undersigned does hereby consent that without affecting the liability of the
undersigned under this Guaranty and without notice to the undersigned, time may
be given by Payee to Maker for payment of the Principal Amount and such other
sums and performance of said other terms, covenants and conditions, or any of
them, and such time extended and indulgence granted, from time to time, or Maker
may be dispossessed or Payee may avail itself of or exercise any or all of the
rights and remedies against Maker provided by law or by the Note, and may
proceed either against Maker alone or jointly against Maker and the undersigned
or against the undersigned alone without first prosecuting or exhausting any
remedy or claim against Maker. The undersigned does hereby further consent to
any subsequent change, modification or amendment of the Note in any of its
terms, covenants or conditions, or in the Principal Amount payable thereunder,
or in the

                                      -20-

<PAGE>

term thereof, and to any renewals or extensions thereof, all of which may be
made without notice to or consent of the undersigned and without in any manner
releasing or relieving the undersigned from liability under this Guaranty.

         The undersigned does hereby agree that the bankruptcy of Maker shall
have no effect on the obligations of the undersigned hereunder. The undersigned
does hereby further agree that in respect of any payments made by the
undersigned hereunder, the undersigned shall not have any rights based on
suretyship, subrogation or otherwise to stand in the place of Payee so as to
compete with Payee as a creditor of Maker, unless and until all claims of Payee
under the Note shall have been fully paid and satisfied.

         The undersigned hereby waives and agrees not to assert: (a) any right
to require Payee to proceed against Maker, or any other guarantor or person or
to pursue any other security or remedy before proceeding against the
undersigned; (b) any defense based on the validity or enforceability of the
Note; (c) any right or defense that may arise by reason of the incapacity, lack
of authority, death or disability of Maker or any other person; and (d) any
right or defense arising by reason of the absence, impairment, modification,
limitation, destruction or cessation (in bankruptcy, by an election of remedies,
or otherwise) of the liability of Maker of the subrogation rights of the
undersigned or of the right of the undersigned to proceed against Maker for
reimbursement. The undersigned waives any right, statutory, or otherwise, for
itself to require or for Maker to require Payee to apply rents received toward
the obligations of the undersigned under this Guaranty, or to otherwise
prioritize the receipt of rents as against the obligations of the undersigned
under this Guaranty. The undersigned hereby waives and agrees not to assert (x)
any right or defense based on the absence of any or all presentments, demands
(including demands for performance), notices (including notices of any adverse
change in the financial status of Maker, notices of any other facts which
increase the risk to the undersigned, notices of non-performance and notices of
acceptance of this Guaranty) and protests of each and every kind; (y) the
defense of any statute of limitations in any action under or related to this
Guaranty or the Note; and (z) any right or defense based on a lack of diligence
or failure or delay by Payee in enforcing its rights under this Guaranty or the
Note. The undersigned hereby waives and agrees not to assert or take advantage
of any right to (i) exoneration if Payee's actions shall impair any security or
collateral of the undersigned; (ii) any security or collateral held by Payee;
(iii) require Payee to proceed against or exhaust any security or collateral
before proceeding against the undersigned; and (iv) require Payee to pursue any
right or remedy for the benefit of the undersigned. Without limiting the
generality of any of the covenants and agreements of the undersigned set forth
in this Guaranty, the undersigned hereby waives any and all benefits of the
provisions of Sections 2809, 2810, 2819, 2822, 2845, 2848, 2849 and 2850 of the
California Civil Code and any similar or analogous statutes of California or any
jurisdiction.

         Until all the Maker's obligations under the Lease are fully performed,
the undersigned (a) shall have no right of subrogation or reimbursement against
the Maker by reason of any payments or acts of performance by the undersigned
under this Guaranty, (b) subordinates any liability or indebtedness of the Maker
now or hereafter held by the undersigned to the obligations of the Maker under,
arising out of or related to the Note; and (c) acknowledges that the actions of
Payee may affect or eliminate any rights of subrogation or reimbursement of the
undersigned as against Maker without any liability or recourse against Payee.

                                      -21-

<PAGE>

         Neither this Guaranty nor any of the provisions hereof can be modified,
waived or terminated, except by a written instrument signed by Payee. The
provisions of this Guaranty shall apply to, bind and inure to the benefit of the
undersigned and Payee and their respective heirs, legal representatives,
successors and assigns. As used herein, the term "Maker" means the Maker
specifically named in the Note and also any assignee or transferee of said Note
and any successor to the interests of said Maker, assignee or transferee of such
Note or any part thereof, whether by assignment or otherwise including, without
limitation, any trustee in bankruptcy and any bankruptcy estate of Maker,
Maker's assignee or transferee. The undersigned, if there be more than one,
shall be jointly and severally liable hereunder, and for purposes of such
several liability the word "undersigned" wherever used herein shall be construed
to refer to each of the undersigned parties separately, all in the same manner
and with the same effect as if each of them had signed separate instruments, and
this Guaranty shall not be revoked or impaired as to any of such parties by the
death of another party or by revocation or release of any obligations hereunder
of any other party.

         If Payee should retain counsel and/or institute any suit against
Guarantor to enforce this Guaranty or any covenants or obligations hereunder,
then Guarantor shall pay to Payee, upon demand, all reasonable attorneys' fees,
costs and expenses, including, without limitation, court costs, filing fees,
recording costs, and all other costs and expenses incurred in connection
therewith (all of which are referred to herein as "Enforcement Costs"), in
addition to all other amounts due hereunder. This Guaranty shall be governed by
and construed in accordance with the internal laws of the state of California.
For the purpose solely of litigating any dispute under this Guaranty, the
undersigned submits to the jurisdiction of the courts of the United States of
America and of said state. The undersigned hereby waives any right to trial by
jury and further waives and agrees not to assert or take advantage of any
defense based on the claim that any arbitration decision binding upon Payee or
Maker is not binding on the undersigned.

         Any notice or other communication to be given to Payee or the
undersigned hereunder shall be in writing and sent in accordance with the notice
provisions of the Note. Notices to Payee shall be delivered to Payee's address
set forth in the Note. Notices to the undersigned shall be addressed as follows:
2077 Gateway Place, Suite 500, San Jose, CA 95110, Attention: Finance
Department. In the event Guarantor's notice address as set forth above changes,
Guarantor agrees to provide written notice to Payee of such change in address.

         This Guaranty shall be construed and enforced in accordance with the
laws of the State of California. Any legal action or proceeding with respect to
this Guaranty and any action for enforcement of any judgment in respect thereof
may be brought in the courts of California or the United States of America for
the Northern District of California and by execution and delivery of this
Guaranty, Guarantor hereby accepts unconditionally the non-exclusive
jurisdiction of the aforementioned courts and their respective appellate courts.
Guarantor hereby irrevocably consents to the service of process out of any of
these aforementioned courts in any such action or proceeding by the mailing of
copies thereof by a reputable international courier to Guarantor at the address
provided herein. Guarantor irrevocably waives any objection which it may now or
hereafter have to the laying of venue in any of the courts referred to above
arising out of or in connection any action or

                                      -22-

<PAGE>

proceeding on this Guaranty brought in any of the courts referred to above and
further irrevocably waives and agrees not to plead or claim in any such court
that any such action or proceeding has been brought in an inconvenient forum.

         IN WITNESS WHEREOF, the undersigned has executed this Guaranty as of
the date of the Note.

                                         GUARANTOR:

                                         BACKWEB TECHNOLOGIES, LTD, AN ISRAELI
                                         CORPORATION

                                         By: __________________________________

                                         Name: ________________________________

                                         Title: ________________________________

                                      -23-

<PAGE>

                            LANDLORD ACKNOWLEDGMENTS

STATE OF ____________)
COUNTY OF ___________)  ss:

         I, the undersigned, a Notary Public, in and for the County and State
aforesaid, do hereby certify that ____________________________, personally known
to me to be the __________ President of Equity Office Properties Trust, a
Maryland real estate investment trust, and personally known to me to be the same
person whose name is subscribed to the foregoing instrument, appeared before me
this day in person and acknowledged that as such officer of said entity being
authorized so to do, (s)he executed the foregoing instrument on behalf of said
entity, by subscribing the name of such entity by himself/herself as such
officer, as a free and voluntary act, and as the free and voluntary act and deed
of said entity, for the uses and purposes therein set forth.

         GIVEN under my hand and official seal this ___ day of _________, 20__.

                                                      __________________________
                                                         Notary Public

My Commission Expires: __________

                             TENANT ACKNOWLEDGMENTS
                                   INDIVIDUAL

STATE OF ____________)
COUNTY OF ___________)  ss:

         I, the undersigned, as Notary Public in and for the County and State
aforesaid, do hereby certify that ____________________________, personally known
to me to be the same person whose name is subscribed to the foregoing
instrument, appeared before me this day in person and acknowledged that (s)he
signed the said instrument as a free and voluntary act for the uses and purposes
therein set forth.

         GIVEN under my hand and official seal this ___ day of __________, 20__.

                                                      __________________________
                                                         Notary Public

My Commission Expires: __________

                                   CORPORATION

STATE OF ____________)
COUNTY OF ___________)  ss:

         On this the ___ day of ____________, 20__, before me a Notary Public
duly authorized in and for the said County in the State aforesaid to take
acknowledgments personally appeared __________________________ known to me to be
____________ President of ________________________, one of the parties described
in the foregoing instrument, and acknowledged that as such officer, being
authorized so to do, (s)he executed the foregoing instrument on behalf of said
corporation by subscribing the name of such corporation by himself/herself as
such officer and caused the corporate seal of said corporation to be affixed
thereto, as a free and voluntary act, and as the free and voluntary act of said
corporation, for the uses and purposes therein set forth.

         IN WITNESS WHEREOF, I hereunto set my hand and official seal.

                                                      __________________________
                                                         Notary Public

My Commission Expires: __________

                                      -24-

<PAGE>

                                   PARTNERSHIP

STATE OF ____________)
COUNTY OF ___________)  ss:

         On this the ___ day of ________________, 20__, before me a Notary
Public duly authorized in and for the said County in the State aforesaid to take
acknowledgments personally appeared _____________ known to me to be a general
partner of a partnership known as _______________________________, one of the
parties described in the foregoing instrument, and acknowledged that being
authorized so to do, (s)he executed the foregoing instrument on behalf of said
partnership by subscribing the name of said partnership by himself/herself, as a
free and voluntary act, and as the free and voluntary act of said partnership,
for the uses and purposes therein set forth.

         IN WITNESS WHEREOF, I hereunto set my hand and official seal.

                                                      __________________________
                                                         Notary Public

My Commission Expires: __________

                                      -25-

<PAGE>

                                    EXHIBIT D

                            FORM OF LETTER OF CREDIT

                         [Name of Financial Institution]

                                                   Irrevocable Standby
                                                   Letter of Credit
                                                   No. _________________________
                                                   Issuance Date:_______________
                                                   Expiration Date:_____________
                                                   Applicant:___________________

Beneficiary

_____________________________
_____________________________
_____________________________

Ladies/Gentlemen:

         We hereby establish our Irrevocable Standby Letter of Credit in your
favor for the account of the above referenced Applicant in the amount of FIVE
HUNDRED THOUSAND AND NO/100 U.S. Dollars ($500,000.00) available for payment at
sight by your draft drawn on us when accompanied by the following documents:

1.       An original copy of this Irrevocable Standby Letter of Credit.

2.       Beneficiary's dated statement purportedly signed by an authorized
         signatory or agent reading: "This draw in the amount of
         ______________________ U.S. Dollars ($____________) under your
         Irrevocable Standby Letter of Credit No. ____________________
         represents funds due and owing to us pursuant to the terms of that
         certain lease by and between ______________________, as landlord, and
         _____________, as tenant, and/or any amendment to the lease or any
         other agreement between such parties related to the lease."

         It is a condition of this Irrevocable Standby Letter of Credit that it
will be considered automatically renewed for a one year period upon the
expiration date set forth above and upon each anniversary of such date, unless
at least 60 days prior to such expiration date or applicable anniversary
thereof, we notify you in writing, by certified mail return receipt requested or
by recognized overnight courier service, that we elect not to so renew this
Irrevocable Standby Letter of Credit. A copy of any such notice shall also be
sent, in the same manner, to: Equity Office Properties Trust, 2 North Riverside
Plaza, Suite 2100, Chicago, Illinois 60606, Attention: Treasury Department. In
addition to the foregoing, we understand and agree that you shall be entitled to
draw upon this Irrevocable Standby Letter of Credit in accordance with 1 and 2
above in the event that we elect not to renew this Irrevocable Standby Letter of
Credit and, in addition, you provide us with a dated statement purportedly
signed by an authorized signatory or agent of Beneficiary stating that the

                                      -26-

<PAGE>

Applicant has failed to provide you with an acceptable substitute irrevocable
standby letter of credit in accordance with the terms of the above referenced
lease. We further acknowledge and agree that: (a) upon receipt of the
documentation required herein, we will honor your draws against this Irrevocable
Standby Letter of Credit without inquiry into the accuracy of Beneficiary's
signed statement and regardless of whether Applicant disputes the content of
such statement; (b) this Irrevocable Standby Letter of Credit shall permit
partial draws and, in the event you elect to draw upon less than the full stated
amount hereof, the stated amount of this Irrevocable Standby Letter of Credit
shall be automatically reduced by the amount of such partial draw; and (c) you
shall be entitled to transfer your interest in this Irrevocable Standby Letter
of Credit from time to time and more than one time without our approval and
without charge. In the event of a transfer, we reserve the right to require
reasonable evidence of such transfer as a condition to any draw hereunder.

         This Irrevocable Standby Letter of Credit is subject to the Uniform
Customs and Practice for Documentary Credits (1993 revision) ICC Publication No.
500.

         We hereby engage with you to honor drafts and documents drawn under and
in compliance with the terms of this Irrevocable Standby Letter of Credit.

         All communications to us with respect to this Irrevocable Standby
Letter of Credit must be addressed to our office located at __________________
to the attention of______________________.


                                                    Very truly yours,
                                                    ____________________________

                                                    ____________________________
                                                           [name]
                                                    ____________________________
                                                           [title}

                                      -27-

<PAGE>

                                    EXHIBIT E

                FORM OF ADDITIONAL REDUCTION FEE PROMISSORY NOTE

                                 PROMISSORY NOTE

                                                            SAN JOSE, CALIFORNIA
NOT TO EXCEED $1,000,000.00                             OCTOBER ___, 2003

         FOR VALUE RECEIVED, the undersigned, BACKWEB TECHNOLOGIES INC., A
DELAWARE CORPORATION ("Maker"), unconditionally promises to pay to CA-GATEWAY
OFFICE LIMITED PARTNERSHIP, A DELAWARE LIMITED PARTNERSHIP ("Payee", which term
shall mean the holder, from time to time, of this Note), a principal sum
determined in accordance with the terms hereof but not to exceed ONE MILLION
DOLLARS ($1,000,000.00). Maker shall pay the then current outstanding principal
amount (as determined in accordance with Section 10 of this Note) to Payee on or
before any date due as provided herein (each a "Maturity Date"). Each such
payment shall be made by good and lawful check or money order payable to EQUITY
OFFICE PROPERTIES, and shall be delivered on or before the close of business to
CA-GATEWAY OFFICE LIMITED PARTNERSHIP, P.O. Box 45587, Dept. 13472, San
Francisco, CA 94145-0587, or such other party or place as Payee may designate by
written notice to Maker. None of the sums due hereunder shall be subject to any
claim or offset of any kind or nature whatsoever. The principal owing under this
Note that is not paid when due shall bear interest ("Default Interest") at the
lesser of 18% per annum or the highest rate permitted by law. All Default
Interest shall be computed on the basis of a 360-day year composed of twelve
30-day months. Payee may transfer this Note, in part or in whole to any party
designated by Payee by written notice to Maker.

1.       PERMISSIBLE PREPAYMENTS. The principal amount of this Note may at any
         time and from time to time be prepaid in whole or in part, together
         with interest accrued thereon to the date of such prepayment, without
         premium or penalty, at the place of payment designated above. Partial
         prepayments shall not delay any Maturity Date.

2.       DEFAULT. At the option of Payee, the then-current outstanding but
         unpaid principal amount balance of this Note (as determined in
         accordance with Section 10 of this Note), including all accrued but
         unpaid interest and accrued but unpaid Default Interest, shall become
         immediately due and payable, without notice or demand, upon the
         occurrence at any time of any of the following:

         a.       failure to pay any amounts due pursuant to the terms hereof
                  when due; or

         b.       failure to pay the outstanding balance due hereunder, together
                  with accrued but unpaid interest and accrued but unpaid
                  Default Interest, if any, thereon, upon any Maturity Date,
                  whether by acceleration or otherwise; or

         c.       Maker shall become insolvent, or shall make a transfer in
                  fraud of creditors, or shall commit an act of bankruptcy or
                  shall make an assignment for the benefit of creditors, or
                  Maker shall admit in writing its inability to pay its debts as
                  they become due; or

                                      -28-

<PAGE>

         d.       Maker shall file a petition under any section or chapter of
                  the United States Bankruptcy Code, as amended, pertaining to
                  bankruptcy, or under any similar law or statute of the United
                  States or any State thereof, or Maker shall be adjudged
                  bankrupt or insolvent in proceedings filed against Maker; or a
                  petition or answer proposing the adjudication of Maker as a
                  debtor or its reorganization under any present or future
                  federal or state bankruptcy or similar law shall be filed in
                  any court and such petition or answer shall not be discharged
                  or denied within 60 days after the filing thereof; or

         e.       a receiver or trustee shall be appointed for all or
                  substantially all of the assets of Maker in any proceeding
                  brought by or against Maker and shall not be discharged within
                  60 days after such appointment; or

         f.       failure to pay when due any payment of Rent or other amounts
                  due under certain office lease dated December 23, 1998 (the
                  "Original Lease") by and between Maker and Payee, which
                  Original Lease has been previously amended by that certain 1st
                  Amendment to Lease - Expansion dated as of May 12, 2000 (the
                  "First Amendment") and by that certain 2nd Amendment to Lease
                  - Expansion dated as of November 7, 2000 (the "Second
                  Amendment"), and by that certain Third Amendment of even date
                  herewith (the "Third Amendment", and together with the
                  Original Lease, the First Amendment and the Second Amendment,
                  collectively, the "Lease") for approximately 17,569 rentable
                  square feet in the building commonly known as Gateway Office
                  IIB located at 2077 Gateway Place, San Jose, California; or

         g.       Intentionally omitted.

         The remedies of Payee as provided herein, or at law or in equity, shall
         be cumulative and concurrent, and may be pursued singly, successively,
         or together at the sole discretion of Payee, and may be exercised as
         often as occasion therefor shall occur. The failure at any time to
         exercise any right or remedy shall not constitute a waiver of the right
         to exercise the right or remedy at any other time.

3.       ENFORCEMENT COSTS. If this Note is placed in the hands of an attorney
         for collection or is collected through any legal proceeding, or if
         Payee incurs any costs or expenses in enforcing its rights hereunder,
         the Maker promises to pay expenses, court costs and reasonable
         attorneys' fees, incurred in connection with such matter, and in
         addition to all such costs and expenses, interest thereon from the date
         of such demand until paid at the Default Interest rate.

4.       WAIVER. Presentment, demand, protest, notices of protest, dishonor and
         non-payment of this Note and all notices of every kind are hereby
         waived by Maker. To the extent permitted by applicable law, the defense
         of the statute of limitations is hereby waived by Maker. The Maker
         agrees that the time of payment of principal or interest on this Note
         may be extended, without in any way altering, releasing, affecting or
         limiting the liability of Maker hereunder. Maker acknowledges that the
         provisions of California Civil Code Section 2924(i) are not applicable
         to this Note and expressly waives any rights thereunder.

                                      -29-

<PAGE>

5.       NOTICES. Any notice desired to be given to any other party hereunder
         shall be in writing and delivered by hand or sent by registered or
         certified mail with return receipt requested, or sent by overnight or
         same day commercial courier service at the party's respective notice
         address(es) below. Each notice shall be deemed to have been received or
         given on the earlier to occur of (i) actual delivery or the date on
         which delivery is refused, if delivered by hand delivery, (ii) three
         (3) days after notice is deposited in the U.S. mail, if delivered via
         certified mail, or (iii) one (1) business day after deposit with a
         commercial courier service. Either party may, at any time, change its
         notice address (other than to a P.O. Box) by giving the other party at
         least 10 days advance written notice of the new address in the manner
         described in this Section.

         Payee's address for notices is:

         CA-GATEWAY OFFICE LIMITED PARTNERSHIP
         c/o Equity Office Properties
         1740 Technology Drive, Suite 150
         San Jose, CA 95110
         Attention:  Building Manager

         With a copy to:

         Equity Office Properties Trust
         Two North Riverside Plaza
         Suite 2100
         Chicago, Illinois 60606
         Attention: Regional Counsel - San Jose Region

         Maker's address for notices is:

         Backweb Technologies Inc.
         2077 Gateway Place
         Suite 500
         San Jose, California 95110
         Attention: Finance Department

6.       GUARANTY. As security for the payment of the monies owing under this
         Note, Maker has delivered or has caused to be delivered to Payee a
         Guaranty (the "Guaranty") entered into by Guarantor (as defined in
         Section 10.a below) for the benefit of Payee, which Guaranty secures
         Maker's performance hereunder.

7.       TRIAL BY JURY WAIVER. TO THE EXTENT PERMITTED BY LAW, EACH OF MAKER AND
         PAYEE HEREBY EXPRESSLY WAIVES ANY RIGHT TO TRIAL BY JURY OF ANY ACTION,
         CAUSE OF ACTION, CLAIM, DEMAND OR PROCEEDING ARISING UNDER OR WITH
         RESPECT TO THIS NOTE, OR IN ANY WAY CONNECTED WITH, RELATED TO, OR
         INCIDENTAL TO THE DEALINGS OF MAKER AND PAYEE WITH RESPECT TO THIS NOTE
         OR THE TRANSACTIONS RELATED

                                      -30-

<PAGE>

         HERETO, IN EACH CASE, WHETHER NOW EXISTING OR HEREAFTER ARISING, AND
         WHETHER SOUNDING IN CONTRACT, TORT, OR OTHERWISE. TO THE MAXIMUM EXTENT
         PERMITTED BY LAW, EACH OF MAKER AND PAYEE HEREBY AGREES THAT ANY SUCH
         ACTION, CAUSE OF ACTION, CLAIM, DEMAND, OR PROCEEDING SHALL BE DECIDED
         BY A COURT TRIAL WITHOUT A JURY AND THAT EITHER PARTY MAY FILE AN
         ORIGINAL COUNTERPART OF THIS SECTION WITH ANY COURT OR OTHER TRIBUNAL
         AS WRITTEN EVIDENCE OF THE CONSENT OF MAKER TO THE WAIVER OF ITS RIGHT
         TO TRIAL BY JURY.

8.       MISCELLANEOUS.

         a.       No single or partial exercise of any power hereunder or under
                  the Lease or any other agreement pertaining to the principal
                  and interest due hereunder and/or any Base Rent or Additional
                  Rent or Cash Consideration due under the Lease shall preclude
                  other or further exercise thereof or the exercise of any other
                  power or right. No delay or omission on the part of the Payee
                  in exercising any right hereunder shall operate as a waiver of
                  such right or of any other right under this Note. All remedies
                  of Payee shall be cumulative and concurrent, and may be
                  pursued singularly, successively or concurrent, at the option
                  of Payee.

         b.       Time is of the essence with respect to the performance of the
                  obligations of Maker under this Note.

         c.       The undersigned, if there be more than one, shall be jointly
                  and severally liable hereunder, and for purposes of such
                  several liability the word "undersigned" or "Maker" wherever
                  used herein shall be construed to refer to each of the
                  undersigned parties separately, all in the same manner and
                  with the same effect as if each of them had signed separate
                  instruments, and this Note shall not be revoked or impaired as
                  to any of such parties by the death of another party or by
                  revocation or release of any obligations hereunder of any
                  other party. The term "Maker" shall also include the heirs,
                  successors and assigns of the original named Maker hereunder.

         d.       This Note shall be governed by and construed in accordance
                  with the internal laws of the state where this Note was
                  executed and delivered. For the purpose solely of litigating
                  any dispute under this Note, the Maker submits to the
                  jurisdiction of the courts of said state. The parties
                  acknowledge and agree this Note was executed and delivered in
                  the State of California.

         e.       Any provision of this Note which is unenforceable, invalid or
                  contrary to law, or the inclusion of which would affect the
                  validity, legality or enforcement of this Note, shall be of no
                  effect, and in such case, all the remaining terms and
                  provisions of this Note shall subsist and be fully effective
                  according to the terms of this Note the same as though any
                  such unenforceable, invalid or contrary provision had never
                  been included herein.

         f.       All payments received on account of the indebtedness evidenced
                  by this Note

                                      -31-

<PAGE>

                  shall be applied to principal, interest, Default Interest and
                  any costs and expenses owing to Payee as a result of this
                  Note, in whatever order, combination and amounts as Payee, in
                  its sole and absolute discretion, decides.

         g.       This Note, and the terms and provisions hereof, shall be
                  binding upon the Maker and each Maker's heirs, executors,
                  personal representatives, successors, administrators, and
                  assigns, and shall inure to the benefit of any holder hereof.
                  Payee has the right to sell, assign, pledge, hypothecate or
                  negotiate this Note, and all Payee's rights hereunder, to any
                  person or entity without notice to or consent of any Maker.

         h.       All amounts due hereunder shall be paid without deduction, set
                  off or counterclaim, Maker expressly waiving any such rights
                  to deduction, set off or counterclaim.

         i.       Each signatory of this Note represents hereby that he or she
                  has the authority to execute and deliver the same on behalf of
                  the party hereto for which such signatory is acting.

         j.       Upon receipt by Maker of written notice from Payee of the
                  loss, theft, destruction or mutilation of this Note, Maker
                  will execute and deliver to Payee, in lieu thereof, a
                  replacement note in identical form to this Note and dated as
                  of the date of this Note. Upon delivery to Payee of such
                  replacement note, all references in the Security Documents to
                  this Note shall be deemed to be references to such replacement
                  note.

         k.       ALL AGREEMENTS BETWEEN MAKER AND PAYEE, WHETHER NOW EXISTING
                  OR HEREAFTER ARISING, AND WHETHER WRITTEN OR ORAL, ARE HEREBY
                  EXPRESSLY LIMITED SO THAT IN NO CONTINGENCY OR EVENT
                  WHATSOEVER, WHETHER BY REASON OF ACCELERATION OF THE MATURITY
                  OF THIS NOTE OR OTHERWISE, SHALL THE AMOUNT PAID OR AGREED TO
                  BE PAID TO PAYEE OR THE HOLDER OF THIS NOTE FOR THE USE,
                  FORBEARANCE OR DETENTION OF THE MONEY LOANED PURSUANT HERETO
                  OR OTHERWISE, OR FOR THE PAYMENT OR PERFORMANCE OF ANY
                  COVENANT OR OBLIGATION CONTAINED HEREIN OR IN ANY OTHER
                  DOCUMENT EXECUTED IN CONNECTION HEREWITH, EXCEED THE MAXIMUM
                  AMOUNT PERMISSIBLE UNDER APPLICABLE LAW. IF, FROM ANY
                  CIRCUMSTANCE OR CONTINGENCY WHATSOEVER, FULFILLMENT OF ANY
                  PROVISION HEREOF OR OF ANY OTHER DOCUMENT EXECUTED IN
                  CONNECTION HEREWITH, AT THE TIME PERFORMANCE OF SUCH PROVISION
                  SHALL BE DUE, SHALL INVOLVE TRANSCENDING THE LIMIT OF VALIDITY
                  PRESCRIBED BY LAW, THEN, IPSO FACTO, THE OBLIGATION TO BE
                  FULFILLED SHALL BE REDUCED TO THE LIMIT OF SUCH VALIDITY, AND
                  IF FROM ANY SUCH CIRCUMSTANCE OR CONTINGENCY PAYEE SHALL EVER
                  RECEIVE AS INTEREST OR OTHERWISE AN AMOUNT WHICH WOULD EXCEED
                  THE MAXIMUM RATE OF INTEREST PERMITTED BY APPLICABLE LAW, THE
                  AMOUNT OF

                                      -32-

<PAGE>

                  SUCH EXCESS SHALL BE APPLIED TO A REDUCTION OF THE
                  INDEBTEDNESS EVIDENCED BY THIS NOTE, AND NOT TO THE PAYMENT OF
                  INTEREST, AND IF SUCH EXCESSIVE INTEREST EXCEEDS SUCH
                  INDEBTEDNESS, THE AMOUNT OF SUCH EXCESSIVE INTEREST SHALL BE
                  REFUNDED TO MAKER. IF AT ANY TIME THIS NOTE PRESCRIBES A RATE
                  OF INTEREST IN EXCESS OF THE MAXIMUM RATE PERMITTED BY LAW,
                  ALL SUMS PAID OR AGREED TO BE PAID TO PAYEE FOR THE USE,
                  FORBEARANCE OR DETENTION OF THE MONEY LOANED PURSUANT TO THIS
                  NOTE SHALL BE AMORTIZED, PRORATED, ALLOCATED AND SPREAD
                  THROUGHOUT THE FULL TERM OF SUCH INDEBTEDNESS UNTIL PAYMENT IN
                  FULL, SO THAT THE ACTUAL RATE OF INTEREST ON ACCOUNT OF SUCH
                  INDEBTEDNESS IS UNIFORM THROUGHOUT THE TERM HEREOF. ANY
                  PREPAYMENT OF THE OUTSTANDING PRINCIPAL BALANCE OF THE LOAN
                  MADE PURSUANT TO THE FOREGOING PROVISIONS SHALL BE WITHOUT ANY
                  PREPAYMENT PENALTY OR PREMIUM.

9.       MAKER'S REPRESENTATIONS AND WARRANTIES. Maker hereby represents and
         warrants to Payee as follows:

         a.       Maker is duly formed, validly existing and in good standing
                  under the laws of the State of Delaware.

         b.       Maker has the power and authority to enter into this Note.
                  Maker's representatives are duly authorized to execute and
                  deliver this Note on behalf of Maker and to generally perform
                  Maker's obligations hereunder. This Note does not violate any
                  provision of any agreement or judicial order to which Maker is
                  a party or to which maker is subject.

         c.       Maker has not (i) made a general assignment for the benefit of
                  creditors, (ii) filed any voluntary petition in bankruptcy or
                  suffered the filing of any involuntary petition by Maker's
                  creditors, (iii) suffered the appointment of a receiver to
                  take possession of all, or substantially all, of Maker's
                  assets, (iv) suffered the attachment or other judicial seizure
                  of all, or substantially all, of Maker's assets, (v) admitted
                  in writing its inability to pay its debts as they come due, or
                  (vi) made an offer of settlement, extension or composition to
                  its creditors generally.

10.      DETERMINATION OF PRINCIPAL AMOUNT. The Principal Amount of this Note
         shall equal the total Additional Reduction Fee (as defined below).
         Maker shall pay to Payee, by cashier's or certified check or by wire
         transfer of immediately available funds to an account designated by
         Payee an additional reduction fee (the "Additional Reduction Fee) in
         the amount and on the dates as hereby provided:

         a.       Any sums invested from any source whatsoever (either debt or
                  equity) in Maker and/or BackWeb Technologies Ltd., an Israeli
                  corporation ("Guarantor"), in the aggregate (the "Investment
                  Dollars") commencing on October 1, 2002 through and including
                  June 30, 2005 (the "Investment Period") shall be subject to
                  the following payment schedule: Within 3 business days
                  following receipt, Maker shall pay to Payee (i) 5% of any of

                                      -33-

<PAGE>

                  any Investment Dollars equal to or in excess of $1.00 through
                  and including $2,000,000.00, (ii) 7% of any Investment Dollars
                  in excess of $2,000,000.00 though and including $5,000,000.00,
                  and (iii) 10% of any Investment Dollars in excess of
                  $5,000,000.00. Investment Dollars shall expressly exclude
                  funds received on the exercise of stock options or as part of
                  Tenant's or Guarantor's (as the case may be) Employee Stock
                  Purchase Plan. Further, Investment Dollars shall also exclude
                  funds received in connection with Tenant's or Guarantor's line
                  of credit or factoring activities to the extent Payee
                  reasonably determines that any such amounts constitute debt to
                  Tenant and/or Guarantor, as the case may be.

         b.       Additionally, and notwithstanding the foregoing, if at any
                  time prior to the expiration of the Investment Period, Maker's
                  and/or Guarantor's revenues (as determined in accordance with
                  generally accepted accounting principles and in accordance
                  with the terms of this Note) in any calendar year equal or
                  exceed $20,000,000.00 in total, Maker shall, on or before the
                  earlier of (i) February 15th of the following calendar year or
                  (ii) thirty (30) days following the expiration of the calendar
                  quarter in which Maker's and/or Guarantor's revenues (as
                  determined in accordance with generally accepted accounting
                  principles and in accordance with the terms of this Note)
                  equal or exceed $20,000,000.00 in total, deliver to Payee as
                  part of the Additional Reduction Fee an amount equal to
                  $1,000,000.00 less the amount of any sums paid by Maker to
                  Payee in connection with any Investment Dollars as such
                  payment is described the preceding paragraph (the "Cash
                  Portion of the Additional Reduction Fee"). In no event shall
                  the total Additional Reduction Fee received by Payee exceed
                  $1,000,000.00.

         c.       Maker shall, at the same time that it publicly announces its
                  financial results following the end of each quarter (but in no
                  event more than within forty-five (45) days following the end
                  of each calendar quarter), provide to Payee a written
                  statement prepared by either of an executive officer of Maker,
                  Maker's Vice President of Finance or Maker's certified public
                  accounting firm certifying as true, complete and correct in
                  all material aspects: (a)(x) Maker and/or Guarantor has
                  received no Investment Dollars the previous calendar quarter,
                  or (y) the amount of and other material details regarding the
                  total amount of any Investment Dollars received by Maker
                  and/or Guarantor the previous calendar quarter, and (b) the
                  amount of each of Maker's and Guarantor's revenues for the
                  previous calendar quarter determined in accordance with
                  generally accepted accounting principles. Payee shall have the
                  right to transfer and assign, in whole or in part, all of its
                  rights in and to it's portion of the Investment Dollars and/or
                  the Cash Portion of the Additional Reduction Fee by providing
                  notice to Maker of such transfer at any time (subject to
                  compliance with applicable law). Unless otherwise indicated in
                  writing by Payee, payments of the Additional Reduction Fee
                  shall be delivered by Maker to Payee in accordance with the
                  terms and conditions contained herein. Payee may give Maker
                  written notice ("Review Notice") that Payee intends to review
                  Maker's and/or Guarantor's records with respect to the
                  foregoing. Within a reasonable time after receipt of the
                  Review Notice, Maker shall make all pertinent records
                  available for inspection (at the building

                                      -34-

<PAGE>

                  in which the premises under the Lease is located) that are
                  reasonably necessary for Payee to conduct its review.

                       [SIGNATURES ARE ON FOLLOWING PAGE]

                                      -35-

<PAGE>

         This Note is entered into by Maker upon the date first written above.

                                         MAKER:

                                         BACKWEB TECHNOLOGIES INC., A DELAWARE
                                         CORPORATION

                                         By:      ____________________________

                                         Name:    ____________________________

                                         Title:   ____________________________

                                      -36-

<PAGE>

                                    EXHIBIT F

                                 FORM OF WARRANT

THE SECURITIES EVIDENCED BY THIS WARRANT HAVE NOT BEEN REGISTERED UNDER THE
SECURITIES ACT OF 1933, AS AMENDED, OR APPLICABLE STATE OR FOREIGN SECURITIES
LAWS, AND NO INTEREST MAY BE SOLD, DISTRIBUTED, ASSIGNED, OFFERED, PLEDGED OR
OTHERWISE TRANSFERRED UNLESS (A) THERE IS AN EFFECTIVE REGISTRATION STATEMENT
UNDER SUCH ACT AND APPLICABLE STATE OR FOREIGN SECURITIES LAWS COVERING ANY SUCH
TRANSACTION INVOLVING SAID SECURITIES, (B) THE COMPANY RECEIVES AN OPINION OF
LEGAL COUNSEL FOR THE HOLDER OF THE SECURITIES SATISFACTORY TO THE COMPANY
STATING THAT SUCH TRANSACTION IS EXEMPT FROM REGISTRATION, (C) SUCH TRANSACTION
IS IN COMPLIANCE WITH RULE 144 OF THE ACT, OR (D) THE COMPANY OTHERWISE
SATISFIES ITSELF THAT SUCH TRANSACTION IS EXEMPT FROM REGISTRATION.

No. W- ___
Issued:  [Date of Amendment]                         Warrant to Purchase 200,000
Void: [Date of SevenYear Anniversary]                Ordinary Shares

                           BACKWEB TECHNOLOGIES LTD.

                                    WARRANT

THIS IS TO CERTIFY that, for good and valuable consideration received and
subject to these terms and conditions, CA-GATEWAY OFFICE, LIMITED PARTNERSHIP, A
DELAWARE LIMITED PARTNERSHIP, or such person to whom this Warrant is transferred
(the "HOLDER"), is entitled to exercise this Warrant to purchase from BackWeb
Technologies Ltd., an Israeli corporation (the "COMPANY"), 200,000 fully paid
and nonassessable Ordinary Shares (the "WARRANT SHARES") at a price per share of
U.S. $ 0.66 (the "EXERCISE PRICE") (such number of shares, type of security and
the Exercise Price being subject to adjustment as provided below).

1.       METHOD OF EXERCISE

         1.1      CASH EXERCISE RIGHT

                  This Warrant may be exercised by the Holder, at any time until
[Date of Five-Year Anniversary of Amendment Date] (the "EXERCISE PERIOD"), in
whole or in part, by delivering to the Company at c/o BackWeb Technologies Inc.,
2077 Gateway Place, Suite 500, San Jose, CA 95110 (or such other office or
agency of the Company as it may designate

<PAGE>

by notice in writing to the Holder at the address of the Holder appearing on the
books of the Company) (a) this Warrant certificate, (b) a certified or cashier's
check payable to the Company or a wire transfer in the amount of the Exercise
Price multiplied by the number of shares for which this Warrant is being
exercised (the "PURCHASE PRICE"), and (c) the Notice of Cash Exercise attached
as EXHIBIT A duly completed and executed by the Holder.

         1.2      NET ISSUANCE RIGHT

                  Notwithstanding the payment provisions set forth above, the
Holder may elect to convert this Warrant into Warrant Shares by surrendering
this Warrant at the office of the Company at the address set forth in Section
1.1 and delivering to the Company the Notice of Net Issuance Exercise attached
as EXHIBIT B duly completed and executed by the Holder, in which case the
Company shall issue to the Holder the number of Warrant Shares of the Company
equal to the result obtained by (a) subtracting B from A, (b) multiplying the
difference by C, and (c) dividing the product by A as set forth in the following
equation:

X = (A - B) x C where:
    -----------
    A

                  X    =     the number of Warrant Shares issuable upon
                             net issuance exercise pursuant to the
                             provisions of this Section 1.2.

                  A    =     the Daily Price (as defined below) of one
                             Warrant Share on the date on which the
                             Holder delivers written notice to the
                             Company pursuant to this Section 1.2.

                  B    =     the Exercise Price for one Warrant Share
                             under this Warrant.

                  C    =     the number of Warrant Shares as to which
                             this Warrant is being exercised, as if the
                             Warrant was exercised pursuant to the
                             provisions of Section 1.1.

         If the foregoing calculation results in a negative number, then no
Warrant Shares shall be issued upon net issuance exercise pursuant to this
Section 1.2.

         "DAILY PRICE" of a Warrant Share shall mean:

         (a)      If the Company's Ordinary Shares are listed and traded on the
New York Stock Exchange, Inc. ("NYSE"), the closing price on such day as
reported on the NYSE Composite Transactions Tape;

         (b)      If the Company's Ordinary Shares are not listed and traded on
the NYSE, the closing price on such day as reported by the principal national
securities exchange on which the Ordinary Shares are listed and traded;

         (c)      If the Company's Ordinary Shares are not listed and traded on
any such securities exchange, the last reported sale price on such day on the
National Market of the National Association of Securities Dealers, Inc.
Automated Quotation System ("NASDAQ");

         (d)      If the Company's Ordinary Shares are not traded on the NASDAQ
National

                                      -2-

<PAGE>

Market, but are traded in the over-the-counter market, the average of the
closing bid and asked prices reported on such day; and

         (e)      If none of the above is applicable, the Daily Price shall be
the fair market value of the Ordinary Shares as determined in good faith by the
Company's Board of Directors.

2.       DELIVERY OF STOCK CERTIFICATES; NO FRACTIONAL SHARES

         2.1      Within 10 days after the payment of the Purchase Price
following the exercise of this Warrant (in whole or in part) or after notice of
net issuance exercise and compliance with Section 1.2, the Company at its
expense shall issue in the name of and deliver to the Holder (a) a certificate
or certificates for the number of fully paid and nonassessable Warrant Shares to
which the Holder shall be entitled upon such exercise, and (b) a new Warrant of
like tenor to purchase up to that number of Warrant Shares, if any, as to which
this Warrant has not been exercised if this Warrant has not expired. The Holder
shall for all purposes be deemed to have become the holder of record of such
Warrant Shares on the close of business on the date this Warrant was exercised
(the date the Holder has fully complied with the requirements of Section 1.1 or
1.2), irrespective of the date of delivery of the certificate or certificates
representing the Warrant Shares; provided that, if the date such exercise is
made is a date when the stock transfer books of the Company are closed, such
person shall be deemed to have become the holder of record of such Warrant
Shares at the close of business on the next succeeding date on which the stock
transfer books are open.

         2.2      No fractional shares shall be issued upon the exercise of this
Warrant. In lieu of fractional shares, the Company shall pay the Holder a sum in
cash equal to the Daily Price of the fractional share on the date of exercise.

3.       COVENANTS AS TO WARRANT SHARES

         The Company covenants that at all times during the Exercise Period
there shall be reserved for issuance and delivery upon exercise of this Warrant
such number of Warrant Shares as is necessary for exercise in full of this
Warrant and, from time to time, it will take all steps necessary to provide
sufficient reserves of Warrant Shares.

         The Company hereby represents and warrants to the Holder that: (a) the
Company has all requisite power and authority to enter into and perform its
obligations under this Warrant; (b) as of the date hereof, the capitalization of
the Company is not materially different from its most recent publicly available
filings, specifically its Form 10-Q for the period ended March 31, 2003, and its
Form 10-K for the period ended December 31, 2002; (c) the execution and delivery
by the Company of the Warrant and the performance of all obligations of the
Company hereunder have been duly authorized by all necessary board and
stockholder actions; and (d) all Warrant Shares which may be issued upon the
exercise of the purchase right represented by this Warrant shall, upon issuance,
be duly authorized, validly issued, fully paid and nonassessable, and free of
any liens and encumbrances except for restrictions on transfer provided for
herein or under applicable federal and state securities laws.

4.       ADJUSTMENTS UPON CERTAIN EVENTS

                                      -3-

<PAGE>

         4.1      EFFECT OF REORGANIZATION

         Upon a merger, consolidation, acquisition of all or substantially all
of the property or stock, liquidation or other reorganization of the Company
(collectively, a "REORGANIZATION") during the Exercise Period, as a result of
which the shareholders of the Company receive cash, stock or other property in
exchange for their Warrant Shares, lawful provision shall be made so that the
Holder shall thereafter be entitled to receive, upon exercise of this Warrant,
the number of shares of securities of the successor corporation resulting from
such Reorganization (and cash and other property), to which a holder of the
Warrant Shares issuable upon exercise of this Warrant would have been entitled
in such Reorganization if this Warrant had been exercised immediately prior to
such Reorganization. In any such case, appropriate adjustment (as determined in
good faith by the Company's Board of Directors) shall be made in the application
of the provisions of this Warrant with respect to the rights and interest of the
Holder after the Reorganization to the end that the provisions of this Warrant
(including adjustments of the Exercise Price and the number and type of
securities purchasable pursuant to the terms of this Warrant) shall be
applicable after that event, as near as reasonably may be, in relation to any
shares deliverable after that event upon the exercise of this Warrant. Nothing
in this Section 4.1 shall be deemed to extend the Exercise Period set forth in
Section 1.1.

         4.2      ADJUSTMENTS FOR STOCK SPLITS, DIVIDENDS

         If the Company shall subdivide the number of outstanding shares of the
same class as the Warrant Shares into a greater number of shares, or issue a
dividend of Warrant Shares on Warrant Shares, then the Exercise Price in effect
before such dividend or subdivision shall be proportionately reduced and the
number of Warrant Shares at that time issuable pursuant to the exercise of this
Warrant shall be proportionately increased; and, conversely, if the Company
shall contract the number of outstanding shares of the same class as the Warrant
Shares by combining such shares into a smaller number of shares, then the
Exercise Price in effect before such combination shall be proportionately
increased and the number of Warrant Shares at that time issuable pursuant to the
exercise or conversion of this Warrant shall be proportionately decreased. Each
adjustment in the number of Warrant Shares issuable shall be to the nearest
whole share.

         4.3      CERTIFICATE AS TO ADJUSTMENTS

         In the case of any adjustment in the Exercise Price or number and type
of securities issuable upon exercise of this Warrant, the Company will promptly
give written notice to the Holder in the form of a certificate, certified and
confirmed by an officer of the Company, setting forth the adjustment in
reasonable detail.

         4.4      NOTICE OF CERTAIN EVENTS

         The Company has been informed by the Holder that Equity Office
Properties Trust, a Maryland real estate investment trust ("EOPT") and an
affiliate of the initial Holder, intends to qualify as a "real estate investment
trust" for purposes of the Internal Revenue Code of 1986, as amended, and that
maintaining such status is of material concern to EOPT and the initial Holder.
Accordingly, the Company represents and warrants to Holder that as of the

                                      -4-

<PAGE>

date hereof, the Warrant Shares deliverable on the exercise of this Warrant do
not constitute ten percent (10%) or more of either (i) the total voting power or
(ii) the total value of the current outstanding securities of the Company. The
Company shall notify Holder in writing at least twenty (20) days in advance of
any redemption, repurchase, or other actions taken by the Company or any other
person, including but not limited to any additional issuances or adjustments
made pursuant to any provisions of this Warrant, in each case which would cause
the Warrant Shares deliverable on the exercise of this Warrant to constitute ten
percent (10%) or more of either (i) the total voting power or (ii) the total
value of the outstanding securities of the Company. For purposes of this Section
4.4, the term "securities" shall have the meaning used for such term in the
Investment Company Act of 1940, as amended, and the term "value" shall mean,
with respect to securities for which market quotations are readily available,
the market value of such securities and, with respect to any other securities,
the fair value of such securities.

5.       SECURITIES LAWS RESTRICTIONS; LEGEND ON WARRANT SHARES

         5.1      This Warrant and the securities issuable upon exercise have
not been registered under the Securities Act of 1933, as amended (the "Act"), or
applicable state or foreign securities laws, and, except as provided in Section
5.3 below, no interest may be sold, distributed, assigned, offered, pledged or
otherwise transferred to any entity unless (a) there is an effective
registration statement under such Act and applicable state and foreign
securities laws covering any such transaction involving said securities, (b) the
Company receives an opinion of legal counsel for the holder of the securities
satisfactory to the Company stating that such transaction is exempt from
registration, (c) such transaction is in compliance with Rule 144 of the Act, or
(d) the Company otherwise satisfies itself that such transaction is exempt from
registration.

         5.2      A legend setting forth or referring to the above restrictions
shall be placed on this Warrant, any replacement and any certificate
representing the Warrant Shares, and a stop transfer order shall be placed on
the books of the Company and with any transfer agent until such securities may
be legally sold or otherwise transferred.

         5.3      Notwithstanding any other provision of this Warrant, the
Holder may transfer all or part of this Warrant and the Warrant Shares issuable
upon exercise of this Warrant without the prior written consent of the Company:
(i) in the case of a Holder who is a partnership or limited liability company,
to a partner (including a limited partner) of such partnership or a member of
such limited liability company; (ii) to any parent or majority-owned subsidiary
of any Holder or parent of any Holder or any successor of any Holder or any
parent of any Holder; (iii) to (x) any taxable REIT subsidiary of EOPT, or (y)
Equity Office Properties Management Corp., a Delaware corporation, or any one of
its subsidiaries; (iv) to the Amended and Restated Equity Office Properties
Management Corp. Trust dated as of September 30, 2002, of which Equity Office
Properties Management Corp. is the sole beneficiary; or (v) to any "affiliate"
of a Holder (as defined in Rule 1b-2 of the Securities Exchange Act of 1934, as
amended (the "Exchange Act")).

                                      -5-

<PAGE>

6.       EXCHANGE OF WARRANT; LOST OR DAMAGED WARRANT CERTIFICATE

         This Warrant is exchangeable upon its surrender by the Holder at the
office of the Company. Upon receipt by the Company of satisfactory evidence of
the loss, theft, destruction or damage of this Warrant and either (in the case
of loss, theft or destruction) reasonable indemnification or (in the case of
damage) the surrender of this Warrant for cancellation, the Company will execute
and deliver to the Holder, without charge, a new Warrant of like denomination.

7.       NOTICES OF RECORD DATE, ETC.

         In the event of

         (a)      any taking by the Company of a record of the holders of
Warrant Shares for the purpose of determining the holders who are entitled to
receive any dividend or other distribution, or any right to subscribe for,
purchase or otherwise acquire any shares of stock of any class or any other
securities or property, or to receive any other right;

         (b)      any reorganization of the Company, any reclassification or
recapitalization of the capital structure of the Company, or any transfer of all
or substantially all the assets of the Company to, or consolidation or merger
of, the Company with or into any person;

         (c)      any voluntary or involuntary dissolution, liquidation or
winding-up of the Company;

         (d)      any proposed issue or grant by the Company to the holders of
Warrant Shares of any shares of any class or any other securities, or any right
or warrant to subscribe for, purchase or otherwise acquire any units of any
class or any other securities; or

         (e)      any other event as to which the Company is required to give
notice to any holders of Warrant Shares,then and in each such event the Company
will mail to the Holder a notice specifying (i) the date on which any such
record is to be taken, (ii) the date on which any such reorganization,
reclassification, recapitalization, transfer, consolidation, merger,
dissolution, liquidation or winding-up is to take place, and the time, if any is
to be fixed, as to which the holders of record of Warrant Shares or securities
into which the Warrant Shares are convertible shall be entitled to exchange
their shares for securities or other property deliverable on such
reorganization, reclassification, recapitalization, transfer, consolidation,
merger, dissolution, liquidation or winding-up, (iii) the amount and character
of any stock or other securities, or rights or warrants, proposed to be issued
or granted, the date of such proposed issue or grant and the persons or class of
persons to whom such proposed issue or grant is to be offered or made, and (iv)
in reasonable detail, the facts, including the proposed date, concerning any
other such event. Such notice shall be delivered to the Holder at least 30
business days prior to the date specified in the notice.

         During such notice period, Holder may exercise this Warrant in
accordance with its terms, and may make such exercise contingent upon the
happening of such event and/or the existence of a minimum value of the Warrant
Shares receivable upon exercise as provided on Holder's exercise notice;
provided that such minimum value shall be no greater than the per share price
set forth in the Company notice.

                                      -6-

<PAGE>

8.       INVESTMENT INTENT

         The Holder is an accredited investor as defined in Rule 501(a) of
Regulation D promulgated under the Act.

         The Holder is aware of the Company's business affairs and financial
condition and has acquired sufficient information about the Company to reach an
informed and knowledgeable decision to acquire this Warrant and the Warrant
Shares. The Holder is acquiring this Warrant and the Warrant Shares issuable
upon exercise thereof for its own account, to hold for investment, and not with
a view to or for sale in connection with any distribution thereof in violation
of the Act, and, upon any exercise of this Warrant, the Holder shall confirm the
same in writing, by executing the form attached as EXHIBIT C hereto. Except as
permitted in Section 5.3, the Holder shall not make any sale, transfer or other
disposition of this Warrant or any Warrant Shares issuable upon exercise thereof
in violation of the Act or the General Rules and Regulations promulgated
thereunder by the Securities and Exchange Commission (the "SEC") or in violation
of any applicable state or foreign securities law.

         The Holder has been advised that this Warrant, and the Warrant Shares
issuable upon exercise thereof, have not been registered under the Act or state
or foreign securities laws in reliance upon an exemption from registration, and
that reliance by the Company on such exemptions is predicated in part on
Holder's representations set forth herein.

         The Holder has been informed that under the Act, this Warrant and the
Warrant Shares issuable upon conversion thereof must be held indefinitely unless
subsequently registered under the Act or unless an exemption from such
registration (such as Rule 144) is available with respect to any proposed
transfer or disposition by the Holder. The Holder further agrees that the
Company may refuse to permit the Holder to sell, transfer or dispose of this
Warrant, and the Warrant Shares issuable upon conversion thereof (except as
permitted under Rule 144) unless there is in effect a registration statement
under the Act and any applicable state or foreign securities laws covering such
transfer, or unless the Holder furnishes an opinion of counsel reasonably
satisfactory to counsel for the Company, to the effect that such registration is
not required; provided, however, such opinion will not be required in connection
with a transfer in compliance with Rule 144 or to a subsidiary or an affiliate
of the Holder pursuant to Section 5.3.

         With a view to making available to the Holder the benefits of Rule 144
and any other rule or regulations of the SEC that may at any time permit Holder
to sell securities of the Company to the public without registration, the
Company agrees to use commercially reasonable efforts to:

                           (a)      file with the SEC in a timely manner all
reports and other documents required of the Company under the Act and the
Exchange Act; and

                           (b)      furnish to Holder, so long as the Holder
owns the Warrant or any Warrant Shares issuable upon conversion thereof,
forthwith upon request (i) a

                                      -7-

<PAGE>

copy of the most recent annual or quarterly report of the Company and such other
reports and documents so filed by the Company, and (ii) such other information
as may be reasonably requested to avail Holder of any rule or regulation of the
SEC that permits the selling of any such securities without registration or
pursuant to such form.

9.       MISCELLANEOUS

         9.1      HOLDER AS OWNER

         The Company may deem and treat the holder of record of this Warrant as
the absolute owner for all purposes regardless of any notice to the contrary.

         9.2      NO SHAREHOLDER RIGHTS

         This Warrant shall not entitle the Holder to any voting rights or any
other rights as a shareholder of the Company or to any other rights except the
rights stated herein; and no dividend or interest shall be payable or shall
accrue in respect of this Warrant or the Warrant Shares, until this Warrant is
exercised.

         9.3      NOTICES

         Unless otherwise provided, any notice under this Warrant shall be given
in writing and shall be deemed effectively given (a) upon personal delivery to
the party to be notified, (b) upon confirmation of receipt by fax by the party
to be notified, (c) two business days after deposit with a reputable overnight
courier, prepaid for overnight delivery and addressed as set forth in (d), or
(d) five days after deposit with the United States Post Office or any foreign
postal service, postage prepaid, registered or certified with return receipt
requested and addressed to the party to be notified at the address indicated
below, or at such other address as such party may designate by 10 days' advance
written notice to the other party given in the foregoing manner.

If to the Holder:

                           CA-Gateway Office Limited Partnership
                           c/o Equity Office Properties Trust
                           1740 Technology Drive, Suite 150
                           San Jose, CA 95110
                           Attn: Peter D. Setzer
                           Facsimile: (408) 467-8979
                           Phone: (408) 487-4119

With a copy to:

                           Equity Office Properties Trust
                           Two North Riverside Plaza, Suite 2100
                           Chicago, IL 60606
                           Attn: Chief Legal Counsel
                           Facsimile: (312) 559-5021
                           Phone: (312) 466-3362

                                      -8-

<PAGE>

If to the Company:

                           BackWeb Technologies Ltd.
                           c/o BackWeb Technologies Inc.
                           2077 Gateway Place, Suite 500
                           San Jose, CA 95110
                           Attn: Chief Financial Officer
                           Facsimile: (408) 933-1800
                           Phone: (408) 933-1731

         9.4      AMENDMENTS AND WAIVERS

         Any term of this Warrant may be amended and the observance of any term
may be waived (either generally or in a particular instance and either
retroactively or prospectively) only with the written consent of the Company and
the Holder. Any amendment or waiver effected in accordance with this Section 9.4
shall be binding on each future Holder and the Company.

         9.5      GOVERNING LAW

         This Warrant shall be governed by and construed under the laws of the
state of California without regard to principles of conflict of laws.

         9.6      SUCCESSORS AND ASSIGNS; TRANSFER

         The terms and conditions of this Warrant shall inure to the benefit of
and be binding on the respective successors and assigns of the parties. This
Warrant may not be transferred or assigned without the consent of the Company,
except, subject to applicable U.S., state, and foreign securities laws, to a
subsidiary or an affiliate of the Holder pursuant to Section 5.3.

                            [Signature page follows.]

                                      -9-

<PAGE>

IN WITNESS WHEREOF, the parties have executed this Warrant as of the date first
written above.

         BACKWEB TECHNOLOGIES LTD.
         By:____________________________________
         Name:  Michael A. Morgan
         Title:  Chief Financial Officer

CA-GATEWAY OFFICE LIMITED PARTNERSHIP, A DELAWARE LIMITED PARTNERSHIP

By: EOM GP, L.L.C., a Delaware limited liability company, its general partner

         By: Equity Office Management, L.L.C., a Delaware limited liability
             company, its non-member manager

             By:__________________________________________
             Name:________________________________________
             Title:_______________________________________

                                      -10-

<PAGE>

                                                                       EXHIBIT A

                                    EXHIBIT A

                             NOTICE OF CASH EXERCISE

To : BackWeb Technologies Ltd.

         The undersigned hereby irrevocably elects to purchase ___________
Ordinary Shares of BackWeb Technologies Ltd. (the "COMPANY") issuable upon the
exercise of the attached Warrant and requests that certificates for such shares
be issued in the name of and delivered to the address of the undersigned stated
below and, if said number of shares shall not be all the shares that may be
purchased pursuant to the attached Warrant, that a new Warrant evidencing the
right to purchase the balance of such shares be registered in the name of, and
delivered to, the undersigned at the address stated below. The undersigned
agrees with and represents to the Company that said shares are acquired for the
account of the undersigned for investment and not with a view to, or for sale in
connection with, any distribution or public offering within the meaning of the
Securities Act of 1933, as amended.

     Payment enclosed in the amount of $___________.

     Dated:  ________________

     Name of Holder of Warrant:_______________________________________
                                         (Please print)

     Address:__________________________________________________________

     Signature: _______________________________________________________

                                        1

<PAGE>

                                    EXHIBIT B

                         NOTICE OF NET ISSUANCE EXERCISE

To:   BackWeb Technologies Ltd.

         The undersigned hereby irrevocably elects to convert the attached
Warrant into such number of shares of Ordinary Shares of BackWeb Technologies
Ltd. (the "COMPANY") as is determined pursuant to Section 1.2 of the attached
Warrant. The undersigned requests that certificates of such net issuance shares
be delivered to the address of the undersigned stated below. The undersigned
agrees with and represents to the Company that said shares are acquired for the
account of the undersigned for investment and not with a view to, or for sale in
connection with, any distribution or public offering within the meaning of the
Securities Act of 1933, as amended.

     Dated: ________________

     Name of Holder of Warrant:___________________________________________
                                        (Please print)

     Address:   __________________________________________________________

     Signature: __________________________________________________________

                                       1

<PAGE>

                                    Exhibit C

                           INVESTMENT REPRESENTATIONS

         THIS AGREEMENT MUST BE COMPLETED, SIGNED AND RETURNED TO BACKWEB
TECHNOLOGIES LTD. ALONG WITH THE NOTICE OF EXERCISE OR NOTICE OF NET ISSUANCE
EXERCISE, AS THE CASE MAY BE BEFORE THE STOCK ISSUABLE UPON EXERCISE OF THE
WARRANT DATED [Date of Amendment] WILL BE ISSUED.

                                ______________, 20__

         BackWeb Technologies Ltd.
         3 Abba Hillel Street
         Ramat Gan, Israel
         Attn:  Chief Executive Officer

         Ladies and Gentlemen:

                  The undersigned, ____________ ("Purchaser"), intends to
acquire up to _______ shares of the Ordinary Shares (the "Ordinary Shares") of
BackWeb Technologies Ltd. (the "Company") from the Company pursuant to the
exercise of that certain Warrant held by Purchaser. The Stock will be issued to
Purchaser in a transaction not involving a public offering and pursuant to an
exemption from registration under the Securities Act of 1933, as amended (the
"1933 Act") and applicable state securities laws. In connection with such
purchase and in order to comply with the exemptions from registration relied
upon by the Company, Purchaser represents, warrants and agrees as follows:

                  Purchaser is an accredited investor as defined in Rule 501(a)
of Regulation D promulgated under the Securities Act.

                  Purchaser is acquiring the Ordinary Shares for its own
account, to hold for investment, and not with a view to or for sale in
connection with any distribution of the Ordinary Shares in violation of the 1933
Act. Purchaser shall not make any sale, transfer or other disposition of the
Ordinary Shares in violation of the 1933 Act or the General Rules and
Regulations promulgated thereunder by the Securities and Exchange Commission
(the "SEC") or in violation of any applicable state securities law.

                                       1

<PAGE>

                  Purchaser has been advised that the Ordinary Shares have not
been registered under the 1933 Act or state securities laws on the ground that
this transaction is exempt from registration, and that reliance by the Company
on such exemptions is predicated in part on Purchaser's representations set
forth in this letter.

                  Purchaser has been informed that under the 1933 Act, the
Ordinary Shares must be held indefinitely unless it is subsequently registered
under the 1933 Act or unless an exemption from such registration (such as Rule
144) is available with respect to any proposed transfer or disposition by
Purchaser of the Ordinary Shares. Purchaser further agrees that the Company may
refuse to permit Purchaser to sell, transfer or dispose of the Ordinary Shares
(except as permitted under Rule 144) unless there is in effect a registration
statement under the 1933 Act and any applicable state securities laws covering
such transfer, or unless Purchaser furnishes an opinion of counsel reasonably
satisfactory to counsel for the Company, to the effect that such registration is
not required; provided, however, such opinion will not be required in connection
with a transfer in compliance with Rule 144 or to a subsidiary of the Purchaser.

                  Purchaser also understands and agrees that there will be
placed on the certificate(s) for the Ordinary Stock, or any substitutions
therefor, a legend stating in substance:

                  THE SECURITIES EVIDENCED BY THIS CERTIFICATE HAVE NOT BEEN
REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR APPLICABLE STATE OR
FOREIGN SECURITIES LAWS, AND NO INTEREST MAY BE SOLD, DISTRIBUTED, ASSIGNED,
OFFERED, PLEDGED OR OTHERWISE TRANSFERRED UNLESS (A) THERE IS AN EFFECTIVE
REGISTRATION STATEMENT UNDER SUCH ACT AND APPLICABLE STATE OR FOREIGN SECURITIES
LAWS COVERING ANY SUCH TRANSACTION INVOLVING SAID SECURITIES, (B) THE COMPANY
RECEIVES AN OPINION OF LEGAL COUNSEL FOR THE HOLDER OF THE SECURITIES
SATISFACTORY TO THE COMPANY STATING THAT SUCH TRANSACTION IS EXEMPT FROM
REGISTRATION, (C) SUCH TRANSACTION IS IN COMPLIANCE WITH RULE 144 OF THE ACT, OR
(D) THE COMPANY OTHERWISE SATISFIES ITSELF THAT SUCH TRANSACTION IS EXEMPT FROM
REGISTRATION.

                  Purchaser has carefully read this letter and has discussed its
requirements and other applicable limitations upon Purchaser's resale of the
Ordinary Shares with Purchaser's counsel.

                                       Very truly yours,

                                       ________________________________________

                                       2

<PAGE>

                                       By: _____________________________________

                                       Title: __________________________________

                                       3

<PAGE>

                                   ASSIGNMENT

         For value received the undersigned sells, assigns and transfers to the
transferee named below, and the transferee agrees to be bound by all the terms
and conditions of, the attached Warrant, together with all right, title and
interest, and the undersigned does irrevocably constitute and appoint the
transfer agent of BackWeb Technologies Ltd. (the "COMPANY") as the undersigned's
attorney, to transfer said Warrant on the books of the Company, with full power
of substitution in the premises.

     Dated:  ________________

     Name of Holder of Warrant:______________________________________________
                                         (Please print)

     Address: _____________________________________________________________

     Signature:_____________________________________________________________

     Signature of Transferor: ______________________________________________

     Name of transferee: ____________________________________________________
                                      (please print)
     Address of transferee:__________________________________________________

     Signature of Transferee: _______________________________________________