<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM ALLAIRE
CORPORATION FINANCIAL STATEMENTS AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE
TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000

                             
<PERIOD-TYPE>                   9-MOS
<FISCAL-YEAR-END>                          DEC-31-1999
<PERIOD-END>                               SEP-30-1999
<CASH>                                          31,031
<SECURITIES>                                    25,745
<RECEIVABLES>                                    6,960
<ALLOWANCES>                                     (570)
<INVENTORY>                                        172
<CURRENT-ASSETS>                               123,345
<PP&E>                                           8,896
<DEPRECIATION>                                 (3,851)
<TOTAL-ASSETS>                                 129,031
<CURRENT-LIABILITIES>                           27,387
<BONDS>                                              0
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                           260
<OTHER-SE>                                     100,708
<TOTAL-LIABILITY-AND-EQUITY>                   129,031
<SALES>                                         29,976
<TOTAL-REVENUES>                                36,837
<CGS>                                            1,771
<TOTAL-COSTS>                                    7,111
<OTHER-EXPENSES>                                36,897
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                                 259
<INCOME-PRETAX>                                (5,787)
<INCOME-TAX>                                         0
<INCOME-CONTINUING>                            (5,787)
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                   (5,787)
<EPS-BASIC>                                     (0.27)
<EPS-DILUTED>                                   (0.27)