| speccy | Speccy Snapshot Data |
| spef | Standard Parasitic Exchange Format |
| spentry | Spartan Entry Database |
| spex | SPEX Data |
| spexp | Substance Painter Export Preset Data |
| spf | SQR Portable Format |
| spf | StruCAD 3D Model |
| spfs | Spider File Storage |
| spg | SG TCP Optimizer Backup |
| sph | Altair FEKO TICRA Spherical Data |
| sph | MikuMikuDance Sphere Multiplied Map |
| sph | Ribbons Sphere Definition |
| sphere | Geomview Sphere Data |
| spin | Apple Mac OS X Console Spin Report |
| spinput | Spartan Spinput Format File |
| spj | SPSS Production Job Data |
| spk | SPARKvue v1.0 Data |
| spk2 | SPARKvue v2.0 Data |
| spklab | SPARKvue Lab Project |
| spl | Abacom sPlan Components Database |
| spl | AkAbak Simulation Data |
| spl | Fusion Exported Spline Data |
| spl | LISREL 8 SIMPLIS Syntax Data |
| spl | Windows Spool Data |
| spl | WinView/400 Report Data |
| spl7 | Abacom sPlan 7 Circuit Diagram |
| splan | SPSS Statistics Simulation Plan |
| splf | SecureZIP Spool File |
| splsm | SmartPLS Model Data |
| splt | yDecode Split Data |
