| twbk | NanoDrop Spectrophotometer Workbook Data |
| twbx | Tableau Packaged Workbook |
| twe | ThinkWave Educator Data |
| twf | Tecgraf Web Format |
| twf | TabWorks Data File |
| twg | CARE-S InfoWorks Trade Waste Data |
| twi | SDDS Toolkit Data |
| twk | T-Works Manager Data |
| twm | TheWord Module |
| twrp | TWRP Data |
| tws | TextPad Workspace |
| tww | Tagwrite Template |
| twz | theWord Compressed Archive Module |
| twzip | theWord Compressed Archive Module |
| tx | TX Text Control Data |
| tx0 | Portable Radiation Package Data |
| tx1 | TracerX Log File |
| tx2 | Typequick Data |
| tx3 | Oasis Lite Gazetteer File |
| txa | Midas ViewPoint Text Array List |
| txa | PTC Creo Training File |
| txb | EES Textbook |
| txd | Genomatix Tuxedo Framework Data |
| txf | PTC Creo Cutting Tool Transfer Data |
| txf | TurboTax Tax Exchange Format |
| txm | TrakAxPC Mix File |
| txn | MySpaceIM Conversation Log |
| txn | SAP POS TXN Log File |
| txp | TerraPage Data |
| txtdt | DVD TEXT Data File |
