| rpx | Wii U Executable |
| rsc | SymbianOS Compiled Resource |
| run | TAS Compiled Executable |
| rwn | TAS Compiled Executable |
| rxe | Lego Mindstorms NXT Brick Executable |
| ryb | Raynerboss Executable |
| s1 | Freescale S-record File |
| s2 | Freescale S-record File |
| s2a | SEAL 2 Application |
| s3 | Freescale S-record File |
| sa9 | Hue and Cry Photoshop Plug-in |
| scar | SCAR Script |
| scf | Windows Explorer Shell Command |
| scr | Microsoft Windows Screensaver |
| script | Generic Script |
| seed | Debian Linux Preseed Data |
| self | Coreboot Simple Executable Loader Format Data |
| ser | Java Serialized Object |
| sjo | Java Serialized Object |
| skprx | Sony PS Vita Kernelspace Plugin |
| sl | HP-UX Shared Library |
| so-abi | Cocoa AbiWord Plug-in |
| som | System Object Model Executable |
| sprg | Synclavier Program |
| spss | SPSS Script |
| suprx | Sony PS Vita Userspace Plugin |
| swc | Adobe Flex Component |
| swf | Shockwave Flash |
| swz | Adobe Flex Signed RSL |
| sx | Freescale S-record File |