| .T04 | Tobias Svensson | 3D-kuvatiedostot | Top 4 Compressed Data File | top 4 | Unknown Developer |
| .TABLE1 | Apple | Datatiedostot | Golden Orchard Apple II CD Rom File | Unknown Software | Unknown Developer |
| .TABLES | Apple | Datatiedostot | Golden Orchard Apple II CD Rom File | Unknown Software | Unknown Developer |
| .TAL | Adobe Systems Incorporated | Tekstitiedostot | Adobe TypeAlign Text Illustration File | Unknown Software | Unknown Developer |
| .TALK | Unknown Developer | Datatiedostot | Text To Speech File | Unknown Software | Unknown Developer |
| .TALK2 | Apple | Datatiedostot | Golden Orchard Apple II CD Rom File | Unknown Software | Unknown Developer |
| .TASP | Unknown Developer | Pelitiedostot | Strategy Planner Data File | Tactical Assault Strategy Planner | Unknown Developer |
| .TCO | Unknown Developer | Datatiedostot | T9000 Object Module | Unknown Software | Unknown Developer |
| .TDR | PO KSI | Varmuuskopiointitiedostot | ArVid Tape Backup | Top Draw | Unknown Developer |
| .TDT | Sony | Videotiedostot | AVCHD Thumbnail File | Unknown Software | Unknown Developer |
| .TEASERS2 | Apple | Datatiedostot | Golden Orchard Apple II CD Rom File | Unknown Software | Unknown Developer |
| .TEBK | Unknown Developer | Harvinaiset Tiedostot | Unknown File Type | Unknown Software | Unknown Developer |
| .TECH | Apple | Datatiedostot | Golden Orchard Apple II CD Rom File | Unknown Software | Unknown Developer |
| .TEK | Unknown Developer | Datatiedostot | ASITIC Technology File | ASITIC | Unknown Developer |
| .TELL | Apple | Datatiedostot | Golden Orchard Apple II CD Rom File | Unknown Software | Unknown Developer |
| .TEMP | Safer Networking Ltd. | Harvinaiset Tiedostot | Temporary (Temp) File | Original Program That Created The File | Unknown Developer |
| .TEST | Unknown Developer | Datatiedostot | Testing File | Unknown Software | Unknown Developer |
| .TESTING | Apple | Datatiedostot | Golden Orchard Apple II CD Rom File | Unknown Software | Unknown Developer |
| .TFB | Unknown Developer | Harvinaiset Tiedostot | Unknown Apple II Data File | Unknown Software | Unknown Developer |
| .TFR | LucasArts Entertainment Company, LLC | Pelitiedostot | TIE Fighter Pilot File | Unknown Software | Unknown Developer |
| .TG1 | Unknown Developer | Harvinaiset Tiedostot | On Target Project File | Unknown Software | Unknown Developer |
| .TGR | The U.S. Census Bureau | GIS-tiedostot | Tiger Line Data | Unknown Software | Unknown Developer |
| .THML | Unknown Developer | Sovelluskehittäjän tiedostot | Theological HTML Document | Theological Markup Language (ThML) | Unknown Developer |
| .THW | Unknown Developer | Harvinaiset Tiedostot | Unknown File Type | Unknown Software | Unknown Developer |
| .TICKET | Apple | Datatiedostot | Golden Orchard Apple II CD Rom File | Unknown Software | Unknown Developer |
| .TID | Sony | Videotiedostot | AVCHD Thumbnail File | Unknown Software | Unknown Developer |
| .TIK | Unknown Developer | Sovelluskehittäjän tiedostot | Script File For Game Textures | Unknown Software | Unknown Developer |
| .TILE | XnSoft | Rasterikuvatiedostot | Eclipse Image | Unknown Software | Unknown Developer |
| .TIPS | Apple | Datatiedostot | Golden Orchard Apple II CD Rom File | Unknown Software | Unknown Developer |
| .TJL | Unknown Developer | Varmuuskopiointitiedostot | VAXTPU Editor Backup File | Unknown Software | Unknown Developer |
| .TJT | Unknown Developer | Harvinaiset Tiedostot | Unknown File Type | Unknown Software | Unknown Developer |
| .TJZ | Unknown Developer | Harvinaiset Tiedostot | Unknown File Type | Unknown Software | Unknown Developer |
| .TKI | Unknown Developer | Harvinaiset Tiedostot | Mime: Application/x-tkined | Unknown Software | Unknown Developer |
| .TNL | Unknown Developer | 3D-kuvatiedostot | Thumbnail Image Format | Unknown Software | Unknown Developer |
| .TO | Apple | Datatiedostot | Golden Orchard Apple II CD Rom File | Unknown Software | Unknown Developer |
| .TOAD | Unknown Developer | Harvinaiset Tiedostot | FunkyToad System File | FunkyToad Network | Unknown Developer |
| .TRACKS | Apple | Datatiedostot | Golden Orchard Apple II CD Rom File | Unknown Software | Unknown Developer |
| .TRANSFERIR | Unknown Developer | Harvinaiset Tiedostot | Unknown File Type | Unknown Software | Unknown Developer |
| .TRAVEL | Apple | Datatiedostot | Golden Orchard Apple II CD Rom File | Unknown Software | Unknown Developer |
| .TRD | Marco Pontello | Datatiedostot | TrID Definitions Package | TR Assistant | Unknown Developer |
| .TRIAL | Apple | Datatiedostot | Golden Orchard Apple II CD Rom File | Unknown Software | Unknown Developer |
| .TRIF | Tiling Task Group (TTG) | Rasterikuvatiedostot | Tiled Raster Interchange Format | Unknown Software | Unknown Developer |
| .TRUETYPE | Apple | Datatiedostot | Golden Orchard Apple II CD Rom File | Unknown Software | Unknown Developer |
| .TSH | CENiX, Inc. | Äänitiedostot | Cenix Audio | Unknown Software | Unknown Developer |
| .TTO | Unknown Developer | Harvinaiset Tiedostot | Client Access Data Specification File | Unknown Software | Unknown Developer |
| .TTS | SumTotal Systems | Datatiedostot | ToolBook Translation System File | TrueTime | Unknown Developer |
| .TVLINK | Unknown Developer | Harvinaiset Tiedostot | Uncommon File Extension | Unknown Software | Unknown Developer |
| .TVW | Unknown Developer | Harvinaiset Tiedostot | Uncommon File Extension | Unknown Software | Unknown Developer |
| .TVX | Doug Cutting | Harvinaiset Tiedostot | Apache Lucene Term Vector Index File | Unknown Software | Unknown Developer |
| .TVZ | Unknown Developer | Harvinaiset Tiedostot | Uncommon File Extension | Unknown Software | Unknown Developer |
| .TWN | Unknown Developer | Asetustiedostot | Scanner Settings File | Unknown Software | Unknown Developer |
| .TWO | Apple | Datatiedostot | Golden Orchard Apple II CD Rom File | Unknown Software | Unknown Developer |
| .TXG | ESRI | Harvinaiset Tiedostot | Georeference Subobject File | Unknown Software | Unknown Developer |
| .TXK | Unknown Developer | Tekstitiedostot | Karaoke Song Lyrics | KaraDOS | Unknown Developer |
| .TXM | CFP Software Limited | Datatiedostot | CFPwinMan Document File | Unknown Software | Unknown Developer |
| .TXW | Yamaha Corporation | Äänitiedostot | Yamaha TX16W Audio File | TX16WConverter | Unknown Developer |
| .TY2 | Unknown Developer | Harvinaiset Tiedostot | Gualtieri Theme Maker File | Gualtieri Theme Maker | Unknown Developer |
| .TYP | Unknown Developer | Harvinaiset Tiedostot | Thumbs32 File | Unknown Software | Unknown Developer |
| .TZG | Unknown Developer | Harvinaiset Tiedostot | Uncommon File Extension | Unknown Software | Unknown Developer |
/1 
