| s | Assembly Source Code |
| s5d | STEP 5 Program |
| s5p | STEP 5 Project |
| s7f | STEP 7 Project |
| s7p | STEP 7 Program |
| sa | Unix Shared Library |
| sac | Single Assignment C Code |
| sal | Gupta Scalable Application Language File |
| sap | Stadium Application |
| sapz | Stadium Archive |
| sas | SAS Program |
| sas7bpgm | SAS Stored Program |
| sas7bput | SAS Permanent Utility |
| sas7butl | SAS Utility |
| sass | Syntactically Awesome Stylesheets |
| sbr | Visual Studio Source Browser Data |
| sbsx | Microsoft Storyboard Shapes File |
| sbt | SBT Build Definition |
| sc | Esterel Unsorted Circuit Code |
| sca | Scala InfoChannel Script |
| scala | Scala Source Code |
| scat | RealView Scatter-loading Data |
| scb | Scala InfoChannel Published Script |
| scc | Microsoft Visual SourceSafe File |
| sce | Scilab Script |
| sci | Scilab Macro Definitions |
| scpt | AppleScript Script |
| scptd | AppleScript Script Bundle |
| screen | Indigo Studio Screen Data |
| scro | Amira Script Object |
| scss | SASS CSS File |
| sct | Script Component File |
| sct | Visual FoxPro Form Memo |
| scx | Microsoft Visual FoxPro Form |
| sdef | AppleScript Dictionary Document |
