| Abbreviation | Definition |
|---|---|
| SSQ | ODBC script |
| SST | SSTMAP Satellite image data |
| ST | Scream Tracker Instrument library |
| ST | Smalltalk language source code file (Little Smalltalk) |
| ST | Stamp (NeoPaint) |
| STA | Saved state |
| STA | Stack |
| STA | Statistica Data file |
| STB | Stub library |
| STD | LocoScript Standard |
| STD | State Transition Diagram graphics file |
| STEP | ISO-10303 STEP product data |
| STF | ShrinkToFit Compressed file archive |
| STK | CRiSP Harvest File |
| STK | HyperStudio Stack File |
| STK | MetaMorph Imaging System Discovery - 1 Software Stack file |
| STK | Personal Stock Monitor File |
| STK | Rail3D 2KD/2K3 Stock and Scenery Models file |
| STK | Sticker Store Sticker file |
| STKX | Personal Stock Streamer Portfolio file |