| Abbreviation | Definition |
|---|---|
| STL | Stereolithography Interface Format |
| STM | Prosa State Transition Diagram model file |
| STM | Scream Tracker II Music (4 channel) |
| STMB | Synclavier Timbre File |
| STO | Pascal stub Object file |
| STP | ISO-10303 STEP product data |
| STR | Gate3 table structure file |
| STR | Structure list object file (dBASE Application Generator) |
| STS | Microsoft C/C++ Project STatus information |
| STS | Scream Tracker Song format file |
| STW | SmartTerm for Windows Data file |
| STX | C A- Simply Tax Tax form |
| STX | Music format |
| STX | SmarText Electronic book |
| STY | STYle Library or Sheet |
| SUB | Rational Rose Component package |
| SUD | Symantec Undo Data |
| SUI | Simple User Interface Toolkit library |
| SUM | Summary |
| SUN | Sun Rasterfile Raster graphics |