| stg | STATISTICA Graphics Data |
| sth | Lotus Domino Stash File |
| sti | STATISTICA In-place Database |
| stip | SampleTank 2 Instruments Preset |
| stk | Hyperstudio Stack Data |
| stk | Pivot Animator Stick Figure |
| stkx | Personal Stock Streamer Portfolio Data |
| stl | Macromedia Fireworks Style Library |
| stm | Microsoft Exchange Streaming Media File |
| stm | Nanoeducator File |
| stm | SmartWare Appointment Data |
| stm | STELLA Model |
| stma | eXtendable Wad Editor STMA Data |
| stmb | Synclavier Timbre Data |
| stmi | Adobe PageMill Data |
| stmod | solidThinking Inspire Model |
| stmx | STELLA Model Data |
| stoc | UMDES FSM Stochastic Data |
| storyisttheme | Storyist Theme Data |
| stot | Mac OS X Help Index |
| stp | MotionTracking Statistic Filters and Masking Parameters Data |
| stp | Tekla STEP Data |
| stp | WSxM SPM Processed Data |
| stpg | STP Gate Phonebook Data |
| stppk | SDL Trados Synergy Project Package |
| stpx | SchemaType Compiled Schema |
| str | Altair FEKO Solution Vector Data |
| str | Avantes Avasoft v8 Single Data |
| str | DataPerfect Structural Information Data |
| str | dBASE Structure Object |
