| 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 |
| str | eSignal Story Data |
| str | Ribbons STR Data |
| str | STATISTICA Report File |
| str | STELLA Runtime |
| str | ZENworks Client Inventory Data |
| string | UltraEdit String Data |
| string | Zoom Player General Text Data |
| strn | HyperCard Stack Converter Data |
| sts | AdriPSX Save State |
| sts | MemMaker Status Information File |
| sts | Nimbus 7 SAMS Status Data |
| stt | SPSS Table Template |
