EXHIBIT 21 – SUBSIDIARIES

MICROS SYSTEMS, INC. SUBSIDIARIES

| **Name of Subsidiary**                                   |   | **Jurisdiction   of Incorporation** |
|----------------------------------------------------------|--------|-------------------------------------|
|                                                          |   |                                     |
| Hospitality Technologies, S.A.                           |   | Argentina                           |
| MICROS-Fidelio Australia Pty   Ltd.                      |   | Australia                           |
| Micros-Fidelio Brazil, Ltda.                             |   | Brazil                              |
| Micros-Fidelio (Canada) Ltd.                             |   | Canada                              |
| Micros Fidelio Chile, S.A.                               |   | Chile                               |
| MICROS-Fidelio Information Systems (Shanghai) Co.   Ltd. |   | China                               |
| CommercialWare, Inc.                                     |   | Delaware, USA                       |
| JTECH Communications, Inc.                               |   | Delaware, USA                       |
| MSI Delaware, LLC                                        |   | Delaware, USA                       |
| Fidelio Nordic Oy                                        |   | Finland                             |
| Fidelio Cruise, Inc.                                     |   | Florida, USA                        |
| MICROS-Fidelio France,   S.A.S.                          |   | France                              |
| MICROS-Fidelio GmbH                                      |   | Germany                             |
| Fidelio Cruise GmbH                                      |   | Germany                             |
| MICROS-Fidelio Hong Kong, Ltd.                           |   | Hong Kong                           |
| Fidelio India Private Ltd.                               |   | India                               |
| MICROS-Fidelio (Ireland), Ltd.                           |   | Ireland                             |
| Micros Fidelio Israel Ltd.                               |   | Israel                              |
| MICROS-Fidelio Italia S.r.l.                             |   | Italy                               |
| MICROS-Fidelio Japan Ltd.                                |   | Japan                               |
| MICROS-Fidelio Mexico S.A. de C.V.                       |   | Mexico                              |
| MICROS-Fidelio Worldwide, Inc.                           |   | Nevada, USA                         |
| Fidelio Nordic Norway A/S                                |   | Norway                              |
| Datavantage Corporation                                  |   | Ohio, USA                           |
| MICROS-Fidelio Software   Portugal, ULDA                 |   | Portugal                            |
| Micros Fidelio Caribbean,   Inc.                         |   | Puerto Rico                         |
| MICROS-Fidelio Singapore Pte   Ltd.                      |   | Singapore                           |
| MICROS-Fidelio España S.L.                          |   | Spain                               |
| Fidelio Nordic Sverige A.B.                              |   | Sweden                              |
| Hotelbk A.B.                                             |   | Sweden                              |
| MICROS-Fidelio Thailand Co. Ltd.                         |   | Thailand                            |
| MICROS-Fidelio Systems U.K. Ltd.                         |   | United Kingdom                      |

The Company has additional subsidiaries, which, considered in the aggregate as a single subsidiary, would not constitute a significant subsidiary as of June 30, 2006.

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