SECURITIES & EXCHANGE COMMISSION
                             Washington, D.C. 20549
                             ----------------------

                                  SCHEDULE 13G
                                 (Rule 13d-102)

             INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT
           TO RULES 13d-1(b), (c) AND (d) AND AMENDMENTS THERETO FILED
                              PURSUANT TO 13d-2(b)

                                (Amendment No. )*


                                  ACTUATE CORP.
                                (Name of Issuer)


                         Common Stock, Par Value $0.001
                         (Title of Class of Securities)

                                    00508B102
                                 (CUSIP Number)


                                 March 7, 2008
             (Date of event which requires filing of this statement)


     Check the appropriate box to designate the rule pursuant to which this
Schedule is filed:

     [ ]  Rule 13d-1(b)
     [x]  Rule 13d-1(c)
     [ ]  Rule 13d-1(d)



                               (Page 1 of 5 Pages)
---------------
     *The remainder of this cover page shall be filled out for a reporting
person's initial filing on this form with respect to the subject class of
securities, and for any subsequent amendment containing information which would
alter the disclosures provided in a prior cover page.

     The information required in the remainder of this cover page shall not be
deemed to be "filed" for purposes of Section 18 of the Securities Exchange Act
of 1934 ("Act") or otherwise subject to the liabilities of that section of the
Act but shall be subject to all other provisions of the Act (however, see the
Notes).





CUSIP No. 00508B102                  13G                 Page 2 of 5 Pages


-----------------------------------------------------------------------------
     (1)    NAMES OF REPORTING PERSONS
            I.R.S. IDENTIFICATION NO.
            OF ABOVE PERSONS (ENTITIES ONLY)
            JANA PARTNERS LLC
-----------------------------------------------------------------------------
     (2)    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP **
                                                                  (a) [ ]
                                                                  (b) [ ]
-----------------------------------------------------------------------------
     (3)    SEC USE ONLY
-----------------------------------------------------------------------------
     (4)    CITIZENSHIP OR PLACE OF ORGANIZATION
             DELAWARE
-----------------------------------------------------------------------------
NUMBER OF      (5)  SOLE VOTING POWER
                    3,705,583
SHARES         --------------------------------------------------------------

BENEFICIALLY   (6)  SHARED VOTING POWER
                    0
OWNED BY       --------------------------------------------------------------

EACH           (7)  SOLE DISPOSITIVE POWER
                    3,705,583
REPORTING      --------------------------------------------------------------

PERSON WITH    (8)  SHARED DISPOSITIVE POWER
                    0
-----------------------------------------------------------------------------
     (9)    AGGREGATE AMOUNT BENEFICIALLY OWNED
            BY EACH REPORTING PERSON
             3,705,583
-----------------------------------------------------------------------------
     (10)   CHECK BOX IF THE AGGREGATE AMOUNT
            IN ROW (9) EXCLUDES CERTAIN SHARES **                       [ ]
-----------------------------------------------------------------------------
     (11)   PERCENT OF CLASS REPRESENTED
            BY AMOUNT IN ROW (9)
             6.2%
-----------------------------------------------------------------------------
     (12)   TYPE OF REPORTING PERSON **
                       IA
-----------------------------------------------------------------------------
                     ** SEE INSTRUCTIONS BEFORE FILLING OUT!




CUSIP No. 00508B102                  13G                 Page 3 of 5 Pages


Item 1(a).      Name of Issuer:
                Actuate Corp.

Item 1 (b).     Address of Issuer's Principal Executive Offices:
                2207 Bridgepointe Pkwy Suite 500
                San Mateo, CA 94404

Item 2 (a).     Name of Person Filing:
                JANA Partners LLC

Item 2 (b).     Address of Principal Business Office or, if None, Residence:
                200 Park Avenue, Suite 3300
                New York, New York 10166

Item 2 (c).     Citizenship:

                This Statement is filed by JANA Partners LLC, a Delaware
                limited liability company. JANA Partners LLC is a private
                money management firm which holds the Common Stock of the
                Issuer in various accounts under its management and control.
                The principals of JANA Partners LLC, Barry Rosenstein and Gary
                Claar, are U.S. citizens.

Item 2 (d).     Title of Class of Securities:

                Common Stock, Par Value $0.001

Item 2 (e).     CUSIP No:

                00508B102

Item 3.         If this statement is filed pursuant to Sec. 240.13d-1(b)
                or 240.13d-2(b) or (c), check whether the person filing is a:

         (a) [ ]   Broker or dealer registered under Section 15 of the Act,

         (b) [ ]   Bank as defined in Section 3(a)(6) of the Act,

         (c) [ ]   Insurance Company as defined in Section 3(a)(19) of the
                   Act,

         (d) [ ]   Investment Company registered under Section 8 of the
                   Investment Company Act of 1940,

         (e) [ ]   Investment Adviser in accordance with Rule
                   13d-1(b)(1)(ii)(E),

         (f) [ ]   Employee Benefit Plan or Endowment Fund in accordance
                   with Rule 13d-1(b)(1)(ii)(F),

         (g) [ ]   Parent Holding Company or control person in accordance
                   with Rule 13d-1(b)(1)(ii)(G),

         (h) [ ]   Savings Association as defined in Section 3(b) of the
                   Federal Deposit Insurance Act,





CUSIP No. 00508B102                  13G                 Page 4 of 5 Pages


         (i) [ ]   Church Plan that is excluded from the definition of an
                   investment company under Section 3(c)(14) of the Investment
                   Company Act of 1940,

         (j) [ ]   Group, in accordance with Rule 13d-1(b)(1)(ii)(J).


Item 4.  Ownership

(a)     Amount beneficially owned: 3,705,583
(b)     Percent of Class: 6.2%
(c)     Number of shares as to which JANA Partners LLC has:
            (i)    Sole power to vote or to direct the vote: 3,705,583
            (ii)   Shared power to vote or to direct the vote: 0
            (iii)  Sole power to dispose or to direct the disposition: 3,705,583
            (iv)   Shared power to dispose or to direct the disposition of: 0

Item 5.    Ownership of Five Percent or Less of a Class.
           Not Applicable.

Item 6.    Ownership of More than Five Percent on Behalf of Another Person.
           Not Applicable.

Item 7.    Identification and Classification of the Subsidiary Which Acquired
           the Security Reported on the Parent Holding Company.
           Not Applicable.

Item 8.    Identification and Classification of Members of the Group.
           Not Applicable.

Item 9.    Notice of Dissolution of Group.
           Not Applicable.





CUSIP No. 00508B102                  13G                 Page 5 of 5 Pages


Item 10.   Certification.

         The Reporting Person hereby makes the following certification:

         By signing below we each certify that, to the best of our knowledge and
belief, the securities referred to above were not acquired and are not being
held for the purpose of or with the effect of changing or influencing the
control of the issuer of such securities and were not acquired and are not held
in connection with or as a participant in any transaction having that purpose or
effect.

                                    SIGNATURE

After reasonable inquiry and to the best of our knowledge and belief, we each
certify that the information set forth in this statement is true, complete, and
correct.


DATED:  March 17, 2008




                                  JANA PARTNERS LLC


                                  By: /s/ Barry Rosenstein
                                      -------------------------------------
                                      Barry Rosenstein
                                      Managing Partner


                                  By: /s/ Gary Claar
                                      -------------------------------------
                                      Gary Claar
                                      General Partner