EXHIBIT 21.1 SUBSIDIARIES OF THE REGISTRANT Zentropic Computing, LLC, a Virginia limited liability company Zentropic Computing, Ltd., a United Kingdom corporation United System Engineers, Inc., a Japanese corporation Fireplug Computers Inc., a Vancouver, B.C. corporation INUP S.A., a societe anonyme French corporation Moreton Bay Ventures Pty Ltd, an Australian corporation RT-Control, Inc., a Toronto, Ontario corporation Dry Canyon Devices, Inc., a Delaware corporation Lineo International FSC, Inc., a Virgin Islands corporation Caldera (UK), Ltd., a United Kingdom corporation