| Tallinna Arvutikool OÜ | Harju County |
| Tallinna Tehnikaülikoo - Arvutiteaduse Instituut | Harju County |
| Tallinna Tehnikaülikool - Arvutitehnika instituut | Harju County |
| Tallinna Tehnikaülikool - Infotehnoloogia teaduskond | Harju County |
| Tallinna Tehnikaülikooli - Arvutitehnika instituut | Harju County |
| Tallinna Tehnikaülikool - Infotehnoloogia teaduskond | |
| Tartu Ãœlikool - Arvutiteaduse Instituut | Tartu County |
| Tartu Ãœlikool - Matemaatika-informaatikateaduskond | Tartu County |
| Tartu Teaduspark | Tartu County |
| Tehnikamarket | Harju County |
| Tele2 Eesti AS | Harju County |
| Telefant | Harju County |
| Telegrupp AS | Tartu County |
| Televõrgu AS | Harju County |
| Tigma AS | Harju County |
| Tigusoft | Harju County |
| TK8 Software | Tartu County |
| Toggl OÜ | Harju County |
| Topconf | Harju County |
| Trenet AS | Harju County |
| TTÜ Küberneetika Instituut | Harju County |
| TVG Eesti OÜ | Harju County |
| UCS Estonia OÜ | Harju County |
| Ultima Design.net | Harju County |
| Univoice OÜ | Harju County |
| Uplink | Harju County |
| Uptime OÜ | Harju County |
| Usesoft AS | Harju County |
| Võrguvara AS | Harju County |
| VeebiStuudio | Harju County |
| Vendomar OÜ | Harju County |
| Vertex Estonia AS | Harju County |
| Virtuaal.com OÜ | Harju County |
| Virtuaalserverid | Harju County |
| Vlsi-soc | |
| VMK Tarkvara OÜ | Harju County |
| Voicecom OÜ | Harju County |
| WaveCom AS | Harju County |
| Web2 OÜ | Harju County |
| Webmedia Tallinn | Harju County |
| Webware OÜ | Harju County |
| WebWhistler | Harju County |
| WIFI.ee | Harju County |
| YEInternational AS | Harju County |
| Zero Technologies | Harju County |
| ZeroTurnaround OÜ | Tartu County |
| Zimplit Ltd | Tartu County |
| Zone Media OÜ | Harju County |