| t2l | True2Life Scene |
| t3x | TYPO3 Extension File |
| task | HP Printer Utility Task Plugin |
| tasl | NASL Pedant TASL Script |
| tbp | Aston Toolbar Plug-in |
| tbs | TuneUp Utilities Boot Screen |
| tco2 | TI-Nspire CX II OS Image |
| td | Thunder Incomplete Download |
| td5 | Panasonic KTS Application |
| tdz | Drobo Firmware File |
| teb | TEAC Firmware Update Data |
| temp | General Temporary File |
| tfu | Torpedo Live Firmware Update |
| tgk | Terragen License Key |
| tgp | Terragen Plugin |
| thn | AMC Graphic Workshop Thumbnail |
| tiapp | TiTanium App |
| tip | TuneUp Utilities Icon Package |
| tis | Acronis True Image Script |
| tko | AMX Software Module |
| tls | TuneUp Utilities Logon Screen |
| tmb | Timbuktu Pro Connection Data |
| tmp | General Temporary File |
| tms | Telemate Script |
| tnc | TI-Nspire CAS OS Image |
| tno | TI-Nspire OS Image |
| tnr | GPS Pathfinder Pro XR Firmware |
| tobj | 18 Wheels of Steel: Haulin Game Data |
| tor | BitTorrent Meta File |
| torrent | BitTorrent Meta File |