. . . EXHIBIT 21.1 MRO SOFTWARE, INC. List of Subsidiaries Jurisdiction of Name of Subsidiary Incorporation Ownership - ------------------ ---------------- --------- MRO International Software, Inc. Delaware (1) MRO Security Corporation Massachusetts (1) MRO International Holdings, Inc. Delaware (2) MRO Software, UK Limited United Kingdom (2) MRO Liquidation Co. Limited Canada (2) MRO Software (Canada) Ltd. Canada (2) MRO Software S.A.R.L. France (2) MRO Software Australia Pty. Limited Australia (2) MRO Software GmbH Germany (2) MRO Software NV Netherlands (2) MRO Software AB Sweden (2) MRO Software Japan K.K. Japan (2) MRO Software Thailand Limited Thailand (2) PSDI India Private Limited India (2) MRO Software (Singapore) Pte Ltd Singapore (2) MRO Software do Brasil Ltda. Brazil (3) MRO Software Hong Kong Ltd. Hong Kong (2) MRO Software Korea Co., Ltd. Korea (2) MRO Software Mexico S.A. de C.V. Mexico (2) MRO Software (Shanghai) Co. Ltd China (1) MRO Software Italia s.r.l. Italy (2) MRO.com, Inc. Delaware (1) MRO.com, Limited United Kingdom (4) MRO.com (Asia) Limited Hong Kong (4) Divested Enterprise, Inc. Delaware (1) MainControl, Inc. Delaware (5) MC Holding Corp. I Delaware (5) MC Holding Corp II Delaware (1) MC Holding Corp. III Delaware (1) MainControl Research Ltd. Delaware (6) MainControl (UK) Limited United Kingdom (6) MainControl GmbH Germany (6) MainControl, Ltd. Israel (6&7) Modern Distribution Management, Inc. Minnesota (4) Raptor ASA Corporation Louisiana (1) (1) All of the outstanding capital stock is owned by MRO Software, Inc. (2) All of the outstanding capital stock (other than certain qualifying shares required in the jurisdiction of organization and representing from 0% to 2% of the outstanding capital stock), is owned by MRO International Software, Inc. (3) 4,950 shares are owned by MRO International Software, Inc. and 50 shares are owned by MRO International Holdings, Inc. (4) All outstanding capital stock is owned by MRO.com, Inc. (5) MRO Software Inc. owns 100% of MC Holding Corp. II and MC Holding Corp. III. MC Holding Corp. II and MC Holding Corp. III each hold a 50% interest in MC Holding Corp. I. MC Holding Corp. I owns 100% of MainControl, Inc. MC Holding Corp. I originally owned 100% of Capri Acquisition Corp. which was merged into MainControl, Inc. (6) MainControl, Inc owns 100%. (7) MainControl, Ltd. Israel (The Company holds 3,999 shares and 1 share is held by G.L.E. Trust Services Ltd.) also domesticated in Delaware for tax purposes as MainControl Research Ltd.