Exhibit 4.13 

April 24, 2009 

Unify Corporation
1420 Rocky Ridge
Drive
Roseville, California 95661 

Attention: Todd E. Wille, President and Chief
Executive Officer 

Dear Todd: 

     Reference is hereby
made to the Purchase Agreement, dated as of April 23, 2004 (the “Purchase
Agreement”), among Unify Corporation (the “Company”) and each of Special
Situations Fund III, L.P., Special Situations Cayman Fund, L.P., Special
Situations Private Equity Fund, L.P. and Special Situations Technology Fund,
L.P. (collectively with their successors and assignees, the “Funds”). Pursuant
to the terms of the Purchase Agreement, the Funds acquired, among other things,
warrants (the “Warrants”) that are presently exercisable for an aggregate of
475,456 shares (the “Warrant Shares”) of the Company’s common stock, par value
$0.001 per share (the “Common Stock”). Capitalized terms used herein have the
respective meanings ascribed thereto in the Purchase Agreement unless otherwise
defined herein. 

In order to induce the Funds to exercise the
Warrants, the Company hereby lowers the Warrant Price of the Warrants to $2.50
per Warrant Share (the “Inducement Price”). 

The Funds hereby exercise the Warrants in full
for all of the Warrant Shares at the Inducement Price per share in accordance
with the terms of the Warrants. The Inducement Price shall be payable in cash as
specified in the Warrants. 

The Funds and the Company agree that the exercise
of the Warrants, the payment of the Inducement Price and delivery of the Warrant
Shares to the Funds shall be completed in accordance with the terms of the
Warrants and the Purchase Agreement. Without limiting the generality of the
foregoing, the Company agrees to cause its transfer agent to issue certificates
representing the Warrant Shares to the Funds in such denominations and
registered in such names as the Funds may request, without restrictive legends.


In consideration of the exercise of the Warrants
by the Funds, the Company hereby grants to the Funds new warrants (the “New
Warrants”) to acquire an aggregate of 190,182 shares of Common Stock (the “New
Warrant Shares”) at a warrant price of $2.75 per New Warrant Share (the “New
Warrant Price”). The New Warrants shall be in substantially the form of the
Warrants, except as provided herein. The New Warrants shall be issued in such
denominations and registered in such names as the Funds may request. The Funds
agree that “Excluded Issuances” under the New Warrants shall include the
issuance of Common Stock, “Options” or “Convertible Securities” (as such terms
are defined in the Warrants) pursuant to the terms of the Agreement and Plan of Merger, dated as of April 16, 2009, among the
Company, UCAC, Inc. and AXS-One, Inc. as in effect on the date hereof.





The Company agrees to effect the registration of
the New Warrant Shares for resale by the Funds or their transferees pursuant to
the requirements of the 1933 Act and applicable state securities laws as
promptly as practicable after the date hereof and in any event no later than
August 31, 2009 (the “Filing Deadline”). The Company and the Funds agree that
the terms of the Registration Rights Agreement shall
govern the registration of the New Warrant Shares, except that the “Closing
Date” specified therein shall be deemed to be the date hereof, the “Registrable
Securities” shall be deemed to include the New Warrant Shares and certain
agreements with respect to liquidated damages for failure to meet registration
statement filing and effectiveness deadlines specified therein shall be replaced
by the provisions in the following paragraph. 

In the event the Company fails to file a
registration statement covering the New Warrant Shares by the Filing Deadline,
or the Company fails to cause such registration statement to be declared
effective by November 30, 2009 (the “Effectiveness Deadline”), the Company shall
pay the Funds as liquidated damages and not as a penalty an amount equal to
$5,000 for each 30-day period (or pro rata for any portion thereof) following
the Filing Deadline or the Effectiveness Deadline, as the case may
be.

The Company hereby represents and warrants to the
Funds that: 

     (a) It has full
power and authority and has taken all requisite action on the part of the
Company, its officers, directors and stockholders necessary for (i) the
authorization, execution and delivery of this Agreement, (ii) authorization of
the performance of all obligations of the Company hereunder or thereunder, and
(iii) the authorization, issuance (or reservation for issuance) and delivery of
the New Warrants and the New Warrant Shares. This Agreement and the New Warrants
constitute, or in the case of the New Warrants upon the issuance thereof will
constitute, the legal, valid and binding obligations of the Company, enforceable
against the Company in accordance with their terms, subject to bankruptcy,
insolvency, fraudulent transfer, reorganization, moratorium and similar laws of
general applicability, relating to or affecting creditors’ rights generally;


     (b) The issuance
and sale of the New Warrants and the New Warrant Shares will not obligate the
Company to issue shares of Common Stock or other securities to any other Person
(other than the Funds) and will not result in the adjustment of the exercise,
conversion, exchange or reset price of any outstanding security; 

     (c) The New
Warrants have been duly and validly authorized. Upon the due exercise of the New
Warrants, the New Warrant Shares will be validly issued, fully paid and
non-assessable free and clear of all encumbrances and restrictions, except for
restrictions on transfer imposed by applicable securities laws and except for
those created by the Funds. The Company has reserved a sufficient number of
shares of Common Stock for issuance upon the exercise of the New Warrants, free
and clear of all encumbrances and restrictions, except for restrictions on
transfer imposed by applicable securities laws and except for those created by
the Funds; 




     (d) The execution,
delivery and performance by the Company of this Agreement and the offer,
issuance and sale of the New Warrants and the New Warrant Shares require no
consent of, action by or in respect of, or filing with, any Person, governmental
body, agency, or official other than filings that have been made pursuant to
applicable state securities laws and post-sale filings pursuant to applicable
state and federal securities laws which the Company undertakes to file within
the applicable time periods. The Company has taken all action necessary to
exempt (i) the issuance and sale of the New Warrants, (ii) the issuance of the
New Warrant Shares upon due exercise of the New Warrants, and (iii) the other
transactions contemplated hereby from the provisions of any shareholder rights
plan or other “poison pill” arrangement, any anti-takeover, business combination
or control share law or statute binding on the Company or to which the Company
or any of its assets and properties may be subject and any provision of the
Company’s Certificate of Incorporation or By-laws that is or could reasonably be
expected to become applicable to the Funds as a result of the transactions
contemplated hereby; and 

     (e) The execution,
delivery and performance of this Agreement and the New Warrants by the Company
and the issuance and sale of the New Warrants and the New Warrant Shares will
not conflict with or result in a breach or violation of any of the terms and
provisions of, or constitute a default under (i) the Company’s Certificate of
Incorporation or the Company’s Bylaws, both as in effect on the date hereof, or
(ii)(a) any statute, rule, regulation or order of any governmental agency or
body or any court, domestic or foreign, having jurisdiction over the Company,
any Subsidiary or any of their respective assets or properties, or (b) any
agreement or instrument to which the Company or any Subsidiary is a party or by
which the Company or a Subsidiary is bound or to which any of their respective
assets or properties is subject. 

     The Funds hereby
confirm that the representations and warranties contained in Section 5 of the
Purchase Agreement are true and correct with respect to the Funds, the New
Warrants and the New Warrant Shares as if set forth herein at length.


     The Company hereby
agrees to pay upon demand the reasonable fees and out-of-pocket expenses of
counsel to the Funds incurred in connection with the negotiation and
documentation of the transactions contemplated hereby. 




     If the foregoing
accurately reflects our agreement, please sign this letter agreement in the
space indicated and return a signed counterpart to the undersigned. This letter
agreement may be executed in counterparts, each of which shall be deemed and
original and all of which shall together represent one and the same instrument.
This letter agreement shall be governed by, and construed in accordance with,
the laws of the State of New York, without reference to the choice of law
provisions thereof. 

		SPECIAL SITUATIONS FUND
      III, L.P.  
		SPECIAL SITUATIONS FUND
      III (QP), L.P.  
		SPECIAL SITUATIONS
      PRIVATE EQUITY FUND, L.P.  
		SPECIAL SITUATIONS CAYMAN
      FUND, L.P.  
		SPECIAL SITUATIONS
      TECHNOLOGY FUND, L.P.  
		SPECIAL SITUATIONS
      TECHNOLOGY FUND II, L.P.  
		  
		  
		  
		By:  	/s/ Austin W. Marxe 	 
		Name: Austin W.
      Marxe  
		Title: General
      Partner  



	ACCEPTED AND
      AGREED:  
	  
	UNIFY
      CORPORATION  
	  
	  
	  
	By:  	/s/
      Todd E. Wille 	 
	Name: Todd E. Wille  
	Title: President and
      Chief Executive Officer