| sts | Squeak Source Code |
| stub | Mac OS X Stub Library |
| sty | WinDev Style Data |
| styl | Stylus CSS Script |
| su7 | SAS Utility |
| sum | Scilab Unit Operation Model |
| sum | Stata Checksum File |
| summ | Clapack Blas Testing Data |
| suo | Visual Studio Solution User Options |
| sv | SystemVerilog File |
| svc | Microsoft IIS Special Content File |
| svc | Uniface Service Data |
| svcinfo | Visual Studio WCF Service Information File |
| svclog | WCF Service Trace Viewer Log |
| svcmap | Visual Studio WCF Service Map File |
| svd | CMSIS System View Description Data |
| svdl | Security Validation Description Language Document |
| svelte | Svelte Source Code |
| svf | Xilinx ISE NetGen Assertion Data |
| svh | SystemVerilog Include File |
| svn | Subversion Data File |
| svn-base | Subversion Base Data |
| svn-work | Subversion Cache |
| svntmp | Subversion Temporary Data |
| svq | SAS 6 Sequential Engine View Data |
| sw | Free Pascal Assembler Data |
| swag | Swag Data |
| swc | Shockwave Flash Component Data |
| swd | Shockwave Flash Debug |
| swe | Siebel Web Engine Data |
| swift | Swift Source Code |
| swiftpm | Swift Package Manager Data |
| swp | Omron Syswin API Description |
| swt | Shockwave Flash Template |
| swt | Visual Basic Setup Wizard Template |
| sxp | OpenOffice.org Script |
| syds | Essential Studio Data Sources Data |
| sydx | Syncfusion Dashboard Data |
| sym | Borland C++ Precompiled Header |
| syn | WinDev Synchronization Data |
| sync | Visual Studio Sync Data |
| syp | SYP Script |
| sysml | Systems Modeling Language Document |
| systag | Android System Tag Data |
| syt | Sytes Template File |
| syx | Modula-2 Software Development System SYX Data |
| t | ReaGeniX Code Generator Tester Symbol Table |
| t | Timber Language Source Code |
| t | Tom Source Code |
| t | Turing Source Code |
| t2p | Tex2Page Macro Code |
| t2w | NTgraph Turbo Pascal Data |
| t3i | WebFOCUS TScom3 Script |
| t3o | WebFOCUS TScom3 Log |
| t6i | Mazak 640-MT Mazatrol Program |
| t6m | Matrix Mazatrol Program |
| taasmt | thinAir Assembly Template |
| tab | Apex Engine TAB Data |
| tab | Microsoft SQL Server Table Script |
| tab | thinBasic Adventure Builder Data |
| tacls | Tangible Class Diagram |
| tacont | thinAir Console Template |
| tag | Java Server Page TagFileInfo Data |
| taguit | thinBasic Debugger Data |
| tah | Turbo Assembler Help Data |
| tal | Transaction Application Language Source Code |
| tal | Typed Assembly Language Source Code |
| targets | MSBuild Targets File |
| tastate | Tangible State Diagram |
| tatxtt | thinBasic Text Template |
| tb1 | Borland Turbo C Font Data |
| tbasic | thinBasic Script |
| tbasicc | thinBasic Console Script |
| tbasiccx | thinBasic Encrypted Console Script |
| tbasici | thinBasic Include Script |
| tbasicu | thinBasic Unit Script |
| tbasicx | thinBasic Encrypted Script |
| tbd | Xcode Text-based Definition Data |
| tbk | Visual FoxPro Memo Backup |
| tc | Borland C++ Configuration Data |
| tcc | Turbo C Include Std Data |
| tcf | MityDSP-L138 Configuration Data |
| tch | Turbo C Help |
| tci | MityDSP-L138 Memory Modules Cache |
| tcl | TCL Script |
| tcm | Transputer Development System Occam Comment Text |
| tco | MSX C Temporary Code |
| tcp | Tally Compliant Product Data |
| tcs | Tahoe Server Content Source |
| tcsh | TCSH Shell Script |
| tcut | TestComplete Unit Testing Project Data |
| tcv | SD Test Coverage Vector File |
| tcx | TestComplete Script Extension Package |
| tcz | PSTextMerge Script |
| tcz | TDF Czar Script |
| td | Turbo Debugger Configuration Data |
| td2 | Turbo Debugger for Win32 Configuration Data |
| tda | Java Thread Dump Data |
| tdat | CodeWarrior Data |
| tdb | ProWorx NXT Title Data with Blocking |
| tdbd | TurboDB Database |
| tdf | ProWorx NXT Title Data File |
| tdk | Borland Turbo Debugger Keystroke Recording Data |
| tdl | MathType Translator Definition Language |
| tdl | Tally Definition Language Data |
| tdlog | Microsoft Visual Studio IntelliTrace Log |
| tdm | LabVIEW Binary Measurement with XML Header |
| tdms | LabVIEW TDM Streaming Data |
| tdms_index | LabVIEW TDM Streaming Index |
| tdr | Xilinx ISE Physical DRC Report Data |
| tds | Turbo Debugger Symbols |
| tdw | Turbo Debugger for Windows Data |
| tdx | LabVIEW Binary Measurement Data |
| tdx | Visual FoxPro Offline View |
| tdy | Today BuildProfessional Application Data |
| tec | PDP-10 TECO Macro |
| tem | Microsoft Frontpage Website Template |
| tes | Tool Encapsulation Specification |
| tes5pas | xEdit TES5Edit Script |
| testrunconfig | Visual Studio Test Run Configuration |
| testsettings | Visual Studio Test Settings Data |
| textile | RedCloth Script |
| texture | Diesel Engine Texture Data |
| tf | Xilinx ISE Verilog Test Bench |
| tflite | TensorFlow Lite Model |
| tfp | ProWorx NXT Full Page Data File |
| tfs | Borland Turbo Profiler Statistical Data |
| tgl | IBM MDWorkbench Text Generation Language Script |
| tgml | Tecumseh Group Markup Language Source Code |
| tgn | LaTeX Table Generator Data |
| tgr | Apex Trigger File |
| tgt | Watcom IDE Target File |
| thm | ForeUI Theme Data |
| thor | Thor Source Code |
| thtml | TCL HTML Script |
| ti | Timber Language Include File |
| ti | Turing Include File |
| tio | Crestron SIMPL Model Definitions Data |
| tiprogram | TI-BASIC Program |
| tk | Tk Script |
| tkc | WinDev Class Data |
| tke | WinDev Report Archive |
| tkg | WinDev Procedures Archive |
| tkh | WinDev Help Archive |
| tkm | tkMOO-light Script |
| tkn | Liberty BASIC Tokenized Source |
| tkp | WinDev Project Archive |
| tkr | WinDev Results Archive |
| tkw | WinDev Windows Archive |
| tla | Temporal Logic of Actions Data |
| tlb | Visual Basic OLE Type Library |
| tld | Tag Library Descriptor |
| tlf | OpenGL Stonehenge Data |
| tlh | Visual C++ TLH Header |
| tli | Visual C++ TLI Header |
| tlt | TList Data |
| tmac | Troff Macros File |
| tmc | Windows Trace Message Control File |
| tmf | Trace Message Format File |
| tmf | Windows Trace Message Format File |
| tmh | Windows Trace Message Header File |
| tmk | Turbo Pascal Tour Data |
| tml | Tapestry Markup Language Document |
| tmml | Tcl Manual Markup Language File |
| tmpl | BlueJ Template File |
| tmx | Translation Memory Exchange Document |
| tnm | Synopsys Synplify Time Names Data |
| toc | Troff Table of Contents Data |
| tok | Borland C++ External Tokens File |
| tombstone | Android System Tombstone Data |
| toml | TOML Source Code |
| tools | DJGPP Tools Data |
| tox | TouchDesigner Component Data |
| tp1 | SPLat Active Template |
| tph | Turbo Pascal Help |
| tpl | BestAddress HTML Editor Template |
| tpm | IBM RSA Transformation Parameters Model |
| tpp | Turbo Pascal Protected Mode Unit |
| tpu | Turbo Pascal Unit |
| tpw | Turbo Pascal Windows Unit |
| tpx | Turbo Pascal 7 Unit |
| tpy | TwinCAT PLC Project Variables |
| tpz | Godot Engine Export Template Archive |
| tr | TCL Trace Output |
| tr | Turbo Debugger Session-state Settings |
| tra | True BASIC Applet |
| tra | µVision Trace Output |
| trb | Amazon Lumberyard Terrain Block Data |
| trb | Turbo STK Application |
| trc | Hitachi Ladder Editor Trace File |
| trc | True BASIC Compiled Program |
| trdf | Apache Jena RDF Thrift Data |
| tres | Godot Engine Text Resource Data |
| trs | TURBU Editor RPG Script |
| trs | WinDev HyperFileSQL Transaction Log |
| tru | True BASIC Source Code |
| trw | Turbo Debugger for Windows Session-state Settings |
| trx | Visual Studio Test Results Data |
| trx | WinDev HyperFileSQL Transaction TRX Log |
| ts | Turbulenz Script |
| ts | TypeScript Source Code |
| ts0 | tio32 Script |
| tscn | Godot Engine Text Scene Data |
| tsf | ProWorx NXT Symbol File |
| tsl | TeamSource Data |
| tsn | RatLab Training SFA Network Data |
| tsq | Transact-SQL Script |
| tsql | Microsoft SQL Server Script Template |
| tt | Visual Studio T4 Text Template |
| ttcn | TTCN-3 Script |
| tte | TextTransformer Interpreter |
| ttf | Altera Quartus II Tabular Text Data |
| tti | TextTransformer Script |
| ttinclude | Visual Studio T4 Text Template Include |
| ttr | TextTransformer Productions |
| ttt | TextTransformer Tests |
| ttw | IBM Rational Tau Workspace |
| ttx | TextTransformer Tokens |
| tu | Turing Unit File |
| tui | NI LabWindows User Interface Data |
| tuneao | Aleph One Data |
| tup | Tup Data |
| turboc3 | Borland Turbo C Makefile |
| tv | Xilinx ISE Verilog Test Fixture Data |
| tvhd | Xilinx ISE VHDL Testbench Data |
| tvsconfig | RAD Studio Modeling Configuration |
| twig | Twig Template |
| twr | Xilinx ISE TRACE Timing Report |
| txg | Toad Data Modeler Package |
| txl | TXL Source Code |
| txs | Tiny XML Server Script |
| tyb | Ty-Basic Source Code |
| tzjs | Turbulenz Java Application |
| tzo | Turbulenz Object |
| u2 | IBM Rational Tau U2 Model |
| u2d | Intel Fortran Compiler Internal Build Data |
| ua | UaModeler Model Data |
| uber | Amazon Lumberyard Uber File |
| ubl | TI DaVinci User Boot Loader |
| uc3 | AVR32 UC3 Firmware Image |
| uca | Unicode Collation Algorithm Data |
| ucx | IBM Rational XDE UCX Data |
| udd | OllyDbg Module Info |
| udn | Alpha Five User Definition Data |
| udo | RapidPLUS User Defined Object |
| udr | JADE Unstructured Data Resource |
| uem | UltraEdit Macro Source Code |
| uf | Crestron SIMPL Compile |
| uht | Amulet uHTML GUI Data |
| uhtml | uHTML Document |