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C-ATS
 
                                                               December 18, 1998
 
To Our Stockholders:
 
     I am pleased to inform you that C-ATS Software Inc. (the "Company"), Misys
plc, a public limited company organized under the laws of England ("Misys"), and
its indirect wholly-owned subsidiaries Kirsty, Inc., a Delaware corporation, and
Moxie Acquisition Corp., a Delaware corporation ("Purchaser"), have entered into
an Agreement and Plan of Merger dated December 14, 1998 (the "Merger Agreement")
pursuant to which Purchaser has commenced a cash tender offer (the "Offer") to
purchase all of the outstanding shares of the Company's common stock (the
"Shares") for $7.50 per share. Under the Merger Agreement, the Offer, if
consummated, will be followed by a merger of Purchaser into the Company (the
"Merger") in which any remaining Shares (other than Shares as to which appraisal
rights have been properly exercised and perfected, Shares held in treasury by
the Company or Shares owned by Purchaser or its affiliates) will be converted
into the right to receive $7.50 per Share in cash, without interest.
 
     YOUR BOARD OF DIRECTORS HAS UNANIMOUSLY DETERMINED THAT THE OFFER AND THE
MERGER ARE FAIR TO AND IN THE BEST INTERESTS OF THE COMPANY STOCKHOLDERS AND
RECOMMENDS THAT STOCKHOLDERS ACCEPT THE OFFER AND TENDER THEIR SHARES PURSUANT
TO THE OFFER. YOU ARE ENCOURAGED TO CONSULT WITH YOUR FINANCIAL OR TAX ADVISOR
REGARDING THE IMPACT THEREOF ON YOU PRIOR TO TENDERING YOUR SHARES IN THE OFFER
OR VOTING TO APPROVE THE MERGER.
 
     In arriving at its recommendations, the Board of Directors gave careful
consideration to a number of factors described in the attached Schedule 14D-9
that has been filed with the Securities and Exchange Commission, including,
among other things, the opinion of Broadview International LLC, the financial
advisor retained by the Board of Directors, to the effect that the $7.50 in cash
to be received by the holders of Shares in the Offer and Merger is fair to such
holders from a financial point of view.
 
     In addition to the attached Schedule 14D-9 relating to the Offer, also
enclosed is the Offer to Purchase, dated December 18, 1998, of Purchaser,
together with related materials, including a Letter of Transmittal to be used
for tendering your Shares. These documents set forth the terms and conditions of
the Offer and the Merger and provide instructions as to how to tender your
Shares. We urge you to read the enclosed material carefully.
 
                                          On behalf of the Board of Directors,
 
                                          /s/ Rod A. Beckstrom
 
                                          Rod A. Beckstrom
                                          Chairman of the Board
                                          And Chief Executive Officer
 
C-ATS Software Inc.
1870 Embarcadero Road
Palo Alto, CA 94303 USA
Tel: 650.321.3000
Fax: 650.321.3050
www.cats.com