EXHIBIT 8.2




                                March 19, 2002


Board of Directors
Talarian Corporation
333 Distel Circle
Los Altos, California 94022

   Re: Exhibit Tax Opinion to the S-4 Registration Statement Filed in
       Connection With the Merger Transaction Involving TIBCO Software Inc. and
       Talarian Corporation

Gentlemen:


   We have been requested to render this opinion concerning the description of
the material U.S. federal income tax considerations in connection with the
proposed merger (the transaction collectively referred to as the "Merger")
involving Talarian Corporation, a Delaware corporation ("Talarian"), TIBCO
Software Inc., a Delaware corporation ("TIBCO"), and Panther Acquisition Corp.,
a Delaware corporation ("Panther Acquisition") and a wholly owned subsidiary of
TIBCO. The Merger is further described in the Securities and Exchange
Commission Form S-4 Registration Statement filed on February 5, 2002, and
related Exhibits thereto, as thereafter amended at any time to and including
the date hereof (the "S-4 Registration Statement"). This opinion has been
requested solely in connection with the filing of the S-4 Registration
Statement with the Securities and Exchange Commission with respect to the
Merger.


   Pursuant to the applicable corporate laws of the State of Delaware and in
accordance with the Agreement and Plan of Merger by and among TIBCO, Panther
Acquisition, and Talarian dated as of January 4, 2002, and exhibits thereto
(collectively, the "Agreement"), the Merger will be structured as (a) a forward
triangular merger pursuant to which Talarian will merge with and into Panther
Acquisition, with Panther Acquisition continuing as the surviving corporation
and a wholly owned subsidiary of TIBCO, or (b) a reverse triangular merger
pursuant to which Panther Acquisition will merge with and into Talarian, with
Talarian continuing as the surviving corporation and becoming a wholly owned
subsidiary of TIBCO, or (c) a reverse triangular merger (pursuant to which
Panther Acquisition will merge with and into Talarian, with Talarian continuing
as the surviving corporation) followed by a second-step forward triangular
merger pursuant to which the surviving corporation of the reverse triangular
merger will merge with and into another wholly owned subsidiary of TIBCO, with
such subsidiary of TIBCO continuing as the surviving corporation.

   Except as otherwise indicated, capitalized terms used herein have the
meanings set forth in the Agreement. All section references, unless otherwise
indicated, are to the Internal Revenue Code of 1986, as amended (the "Code").

   We have acted as legal counsel to Talarian in connection with the Merger. As
such, and for the purpose of rendering this opinion, we have examined and are
relying upon (without any independent investigation or review thereof) the
truth and accuracy, at all relevant times, of the statements, covenants,
representations and warranties contained in the following documents (including
all schedules and exhibits thereto), among others:

   1.  The S-4 Registration Statement (including exhibits thereto);

   2.  The Agreement; and

   3.  Officers' tax certificates relating to the Merger signed by and received
from authorized officers of the corporate parties to the Merger.



   In addition, in connection with rendering this opinion, we have assumed
(without any independent investigation thereof) that:

   (1)  Original documents (including signatures) are authentic, documents
submitted to us as copies conform to the original documents, and there has been
(or will be by the Effective Time of the Merger) due execution and delivery of
all documents where due execution and delivery are prerequisites to the
effectiveness thereof;

   (2)  Any statements, covenants, representations or warranties referred to
above made "to the best of knowledge," "to the knowledge of" or otherwise
similarly qualified are correct without such qualification. As to all matters
in which a person or entity making a representation referred to above has
represented that such person or entity is not a party to, does not have or is
not aware of, any plan, intention, understanding or agreement, there is in fact
no such plan, intention, understanding or agreement;

   (3)  All statements, covenants, representations and warranties, whether or
not qualified, are true and will remain true through the Effective Date and
thereafter where relevant, and no actions have been (or will be taken) which
are inconsistent with such representations;

   (4)  The Merger will be consummated pursuant to the Agreement and will be
effective under the laws of the state of Delaware; and

   (5)  An opinion of counsel, substantially identical in substance to this
opinion, has been delivered to TIBCO by Venture Law Group, A Professional
Corporation, and will not be withdrawn prior to the Effective Date.

   Based on our examination of the foregoing items and subject to the
assumptions, exceptions, limitations and qualifications set forth herein and in
the S-4 Registration Statement, we are of the opinion that the discussion set
forth in the S-4 Registration Statement under the heading "Proposal No. 1--The
Merger--Material United States Federal Income Tax Considerations" constitutes,
in all material respects, a fair and accurate summary of the U.S. federal
income tax consequences of the Merger generally applicable to a Talarian
stockholder.

   Our opinion set forth above is based on the existing provisions of the Code,
Treasury Regulations (including Temporary Treasury Regulations) promulgated
under the Code, published Revenue Rulings, Revenue Procedures and other
announcements of the Internal Revenue Service and existing court decisions, any
of which could be changed at any time. Any such changes might be retroactive
with respect to transactions entered into prior to the date of such changes and
could significantly modify the opinion set forth above. Nevertheless, we
undertake no responsibility to advise you of any subsequent developments in the
application, operation or interpretation of the U.S. federal income tax laws.

   This opinion is being delivered solely to the board of directors of Talarian
as constituted on the date hereof for the sole purpose of being included as an
exhibit to the S-4 Registration Statement; it may not be relied upon or
utilized for any other purpose (including, without limitation, satisfying any
conditions in the Agreement) or by any other person or entity, and may not be
made available to any other person or entity, without our prior written
consent. We do, however, consent to the filing of this opinion as Exhibit 8.2
to the S-4 Registration Statement and to the use of our name in the S-4
Registration Statement wherever it appears. In giving this consent, however, we
do not hereby admit that we are in the category of persons whose consent is
required under Section 7 of the Securities Act of 1933, as amended (the
"Securities Act"), or the rules or regulations promulgated thereunder, or that
we are experts with respect to any portion of the S-4 Registration Statement
within the meaning of the term "experts" as used in the Securities Act, or the
rules and regulations promulgated thereunder.

                                          Very truly yours,

                                          /s/  FENWICK & WEST LLP
                                          --------------------------------------
                                          FENWICK & WEST LLP
                                          A LIMITED LIABILITY PARTNERSHIP
                                          INCLUDING PROFESSIONAL CORPORATIONS