<PAGE>

EXHIBIT 10.23

                                FOURTH AMENDMENT
                                       TO
                           LOAN AND SECURITY AGREEMENT
                           ---------------------------


         This Fourth Amendment to Loan and Security Agreement is entered into as
of November 15, 2002 (the "Amendment"), by and between COMERICA BANK -
CALIFORNIA ("Bank") and PERSISTENCE SOFTWARE, INC. ("Borrower").

                                    RECITALS
                                    --------

         Borrower and Bank are parties to that certain Amended and Restated Loan
and Security Agreement dated as of March 6, 2002, as amended from time to time
including, but not limited to, by that certain First Amendment to Loan and
Security Agreement dated as of May 6, 2002, that certain Second Amendment to
Loan and Security Agreement dated as of July 3, 2002 and that certain Third
Amendment to Loan and Security Agreement dated as of July 17, 2002
(collectively, the "Agreement"). The parties desire to amend the Agreement in
accordance with the terms of this Amendment.

         NOW, THEREFORE, the parties agree as follows:

         1. Section 6.9 of the Agreement is hereby amended in its entirety to
read as follows:

                  6.9 TANGIBLE NET WORTH. On a consolidated basis, Borrower
         shall maintain a Tangible Net Worth of at least $4,000,000, provided
         that such required amount shall increase by 50% of Borrower's net
         income after taxes in each quarter after November 15, 2002 and by 75%
         of any proceeds received by Borrower from the sale or issuance of its
         equity or debt securities after November 15, 2002. This covenant shall
         be measured as of the last day of each quarter, provided that, at any
         time that the aggregate amount of the outstanding Advances plus the
         aggregate undrawn face amount of all outstanding Letters of Credit is
         in excess of $400,000, this covenant shall be measured as of the last
         day of each month.


         2. EXHIBIT D to the Agreement is hereby amended and replaced in its
entirety by EXHIBIT D attached hereto.

         3. Bank waives failure to comply with Section 6.9 of the Agreement for
the quarter ended on September 30, 2002, as such section was in effect prior to
this Amendment. Bank does not waive any other failure by Borrower to perform its
Obligations under the Loan Documents and Bank does not waive any Obligations
Borrower may have under the Agreement after the date hereof. This waiver is not
a continuing waiver with respect to any failure to perform any Obligation after
the date of this Amendment.

         4. Unless otherwise defined herein, all initially capitalized terms in
this Amendment shall be as defined in the Agreement. The Agreement, as amended
hereby, shall be and remain in full force and effect in accordance with its
respective terms and hereby is ratified and confirmed in all respects. Except as
expressly set forth herein, the execution, delivery, and performance of this
Amendment shall not operate as a waiver of, or as an amendment of, any right,
power, or remedy of Bank under the Agreement, as in effect prior to the date
hereof. Borrower ratifies and reaffirms the continuing effectiveness of the
Agreement and all instruments, documents and agreements entered into in
connection with the Agreement.

         5. Borrower represents and warrants that: (i) the representations and
warranties contained in the Agreement are true and correct as of the date of
this Amendment, (ii) that Borrower is in compliance with the intellectual
property registration requirements set forth in Section 6.10 of the Agreement
and that Borrower has notified Bank of such required registrations in compliance
with Section 6.3 of the Agreement and (iii) that no Event of Default has
occurred and is continuing.

         6. This Amendment may be executed in two or more counterparts, each of
which shall be deemed an original, but all of which together shall constitute
one instrument.

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<PAGE>

         7. As a condition to the effectiveness of this Amendment, Bank shall
have received, in form and substance satisfactory to Bank, the following:

                  (a) this Amendment, duly executed by Borrower;

                  (b) a restructure fee equal to Five Hundred Dollars ($500),
which shall be nonrefundable as of the date of this Amendment and which Bank
shall charge against any of Borrower's deposit accounts with Bank on the date of
this Amendment, plus an amount equal to all Bank Expenses incurred through the
date of this Amendment; and

                  (c) such other documents, and completion of such other
matters, as Bank may reasonably deem necessary or appropriate.

         IN WITNESS WHEREOF, the undersigned have executed this Amendment as of
the first date above written.

                                         PERSISTENCE SOFTWARE, INC.


                                         By: /s/ Christing Russell
                                             -----------------------------------
                                         Title: Chief Financial Officer


                                         COMERICA BANK - CALIFORNIA


                                         By: /s/ Guy Simpson
                                             -----------------------------------
                                         Title: Assistant Vice President

                                       2
<PAGE>

                         CORPORATE RESOLUTIONS TO BORROW
--------------------------------------------------------------------------------
                      BORROWER: PERSISTENCE SOFTWARE, INC.
--------------------------------------------------------------------------------

         I, the undersigned Secretary or Assistant Secretary of PERSISTENCE
SOFTWARE, INC. (the "Corporation"), HEREBY CERTIFY that the Corporation is
organized and existing under and by virtue of the laws of the State of Delaware.

         I FURTHER CERTIFY that attached hereto as Attachments 1 and 2 are true
and complete copies of the Certificate of Incorporation, as amended, and the
Restated Bylaws of the Corporation, each of which is in full force and effect on
the date hereof.

         I FURTHER CERTIFY that at a meeting of the Directors of the
Corporation, duly called and held, at which a quorum was present and voting (or
by other duly authorized corporate action in lieu of a meeting), the following
resolutions were adopted.

         BE IT RESOLVED, that any one (1) of the following named officers,
employees, or agents of this Corporation, whose actual signatures are shown
below:

         NAMES                    POSITION                ACTUAL SIGNATURES
         -----                    --------                -----------------

_________________________  _________________________  _________________________

_________________________  _________________________  _________________________

_________________________  _________________________  _________________________

_________________________  _________________________  _________________________

acting for and on behalf of this Corporation and as its act and deed be, and
they hereby are, authorized and empowered:

         BORROW MONEY. To borrow from time to time from COMERICA BANK -
CALIFORNIA ("Bank"), on such terms as may be agreed upon between the officers,
employees, or agents of the Corporation and Bank, such sum or sums of money as
in their judgment should be borrowed, without limitation.

         EXECUTE LOAN DOCUMENTS. To execute and deliver to Bank that certain
Fourth Amendment dated as of November 15, 2002 (the "Loan Agreement") and any
other agreement entered into between Corporation and Bank in connection with the
Loan Agreement, including any amendments, all as amended or extended from time
to time (collectively, with the Loan Agreement, the "Loan Documents"), and also
to execute and deliver to Bank one or more renewals, extensions, modifications,
refinancings, consolidations, or substitutions for the Loan Documents, or any
portion thereof.

         GRANT SECURITY. To grant a security interest to Bank in the Collateral
described in the Loan Documents, which security interest shall secure all of the
Corporation's Obligations, as described in the Loan Documents.

         NEGOTIATE ITEMS. To draw, endorse, and discount with Bank all drafts,
trade acceptances, promissory notes, or other evidences of indebtedness payable
to or belonging to the Corporation or in which the Corporation may have an
interest, and either to receive cash for the same or to cause such proceeds to
be credited to the account of the Corporation with Bank, or to cause such other
disposition of the proceeds derived therefrom as they may deem advisable.

         LETTERS OF CREDIT. To execute letter of credit applications and other
related documents pertaining to Bank's issuance of letters of credit.

         FURTHER ACTS. In the case of lines of credit, to designate additional
or alternate individuals as being authorized to request advances thereunder, and
in all cases, to do and perform such other acts and things, to pay any and all

                                       3
<PAGE>

fees and costs, and to execute and deliver such other documents and agreements
as they may in their discretion deem reasonably necessary or proper in order to
carry into effect the provisions of these Resolutions.

         BE IT FURTHER RESOLVED, that any and all acts authorized pursuant to
these resolutions and performed prior to the passage of these resolutions are
hereby ratified and approved, that these Resolutions shall remain in full force
and effect and Bank may rely on these Resolutions until written notice of their
revocation shall have been delivered to and received by Bank. Any such notice
shall not affect any of the Corporation's agreements or commitments in effect at
the time notice is given.

         I FURTHER CERTIFY that the officers, employees, and agents named above
are duly elected, appointed, or employed by or for the Corporation, as the case
may be, and occupy the positions set forth opposite their respective names; that
the foregoing Resolutions now stand of record on the books of the Corporation;
and that the Resolutions are in full force and effect and have not been modified
or revoked in any manner whatsoever.

         IN WITNESS WHEREOF, I have hereunto set my hand on November 15, 2002
and attest that the signatures set opposite the names listed above are their
genuine signatures.

                                      CERTIFIED AND ATTESTED BY:


                                      X ________________________________________

________________________________________________________________________________

                                       4
<PAGE>

                                    EXHIBIT D
                             COMPLIANCE CERTIFICATE

TO:               COMERICA BANK - CALIFORNIA
FROM:             PERSISTENCE SOFTWARE, INC.

         The undersigned authorized officer of PERSISTENCE SOFTWARE, INC. hereby
certifies that in accordance with the terms and conditions of the Amended and
Restated Loan and Security Agreement between Borrower and Bank (the
"Agreement"), (i) Borrower is in complete compliance for the period ending
_______________ with all required covenants except as noted below and (ii) all
representations and warranties of Borrower stated in the Agreement are true and
correct as of the date hereof. Attached herewith are the required documents
supporting the above certification. The Officer further certifies that these are
prepared in accordance with Generally Accepted Accounting Principles (GAAP) and
are consistently applied from one period to the next except as explained in an
accompanying letter or footnotes.

                   PLEASE INDICATE COMPLIANCE STATUS BY CIRCLING YES/NO UNDER
"COMPLIES" COLUMN.

<TABLE>
<CAPTION>
<S>     <C>                                                       <C>                                           <C>        <C>
        REPORTING COVENANT                                        REQUIRED                                            COMPLIES
        ------------------                                        --------                                            --------

        Financial statements                                      Quarterly within 45 days (monthly w/in 20     Yes        No
                                                                  days if Line exposure > $400,000)
        Annual (CPA Audited)                                      FYE within 90 days                            Yes        No
        10K and 10Q                                               When filed                                    Yes        No
        A/R Audit                                                 Semi-Annual                                   Yes        No
        A/R & A/P Agings, Borrowing Base Cert.                    Monthly within 15 days if Line exposure >     Yes        No
                                                                  $400,000
        IP Report                                                 Quarterly within 45 days                      Yes        No
        Total amount of Borrower's cash and investments           Amount:  $________                            Yes        No
        Total amount of Borrower's cash and investments           Amount:  $________                            Yes        No
        maintained with Bank

        FINANCIAL COVENANT                                        REQUIRED                 ACTUAL                     COMPLIES
        ------------------                                        --------                 ------                     --------

        Maintain on a Quarterly / Monthly* Basis:
             Minimum Quick Ratio                                  2.00:1.00                _____:1.00           Yes        No
             Minimum Tangible Net Worth                           $4,000,000 increased     $________            Yes        No
                                                                  by 50% of Borrower's
                                                                  quarterly net income
                                                                  after taxes and by 75%
                                                                  of any equity
                                                                  proceeds**
</TABLE>

             * These covenants shall be measured as of the last day of each
             quarter, provided that, at any time that the aggregate amount of
             the outstanding Advances plus the aggregate undrawn face amount of
             all outstanding Letters of Credit is in excess of $400,000, this
             covenant shall be measured as of the last day of each month. ** On
             a consolidated basis, Borrower shall maintain a Tangible Net Worth
             of at least $4,000,000, provided that such required amount shall
             increase by 50% of Borrower's net income after taxes in each
             quarter after the date hereof and by 75% of any proceeds received
             by Borrower from the sale or issuance of its equity or debt
             securities after [the Closing Date/June 30, 2002]. This covenant
             shall be measured as of the last day of each quarter, provided
             that, at any time that the aggregate amount of the outstanding
             Advances plus the aggregate undrawn face amount of all outstanding
             Letters of Credit is in excess of $400,000, this covenant shall be
             measured as of the last day of each month.

<TABLE>
<CAPTION>
<S>                                                              <C>
                                                                 ------------------------------------------------------------------
COMMENTS REGARDING EXCEPTIONS:  See Attached.
                                                                 BANK USE ONLY
                                                                 Received by: _____________________________________________________
Sincerely,                                                                                AUTHORIZED SIGNER

                                                                 Date: ____________________________________________________________

______________________________________________                   Verified: ________________________________________________________
SIGNATURE                                                                                 AUTHORIZED SIGNER

______________________________________________                   Date: ____________________________________________________________
TITLE
                                                                 Compliance Status                              Yes        No
______________________________________________
DATE                                                             ------------------------------------------------------------------
</TABLE>

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