| .rpy |
Touhou Project Replay File |
| .rav |
Rave Reports Project File |
| .resw |
Windows Resources File, Silverlight Applications resource file |
| .rodl |
RemObjects Definition Language File |
| .rs |
Rust Source Code File |
| .rc2 |
Visual Studio Resources File |
| .resjson |
Windows JavaScript Resources File |
| .refresh |
Visual Studio Refresh File |
| .reb |
REBOL Script File |
| .rbxs |
ROBLOX Script |
| .rotest |
RemObjects SDK Test File |
| .rotestresult |
RemObjects SDK Test Results File |
| .rwsnippet |
RapidWeaver Snippet File |
| .rls |
Symbian Localization File |
| .rbm |
Real Studio Menu File |
| .rdoc |
Ruby Document |
| .ru |
Java Russian Font Properties File |
| .rbvcp |
Real Studio Version Controlled Project |
| .rdoc_options |
Ruby Document Options File |
| .sh |
Bash Shell Script |
| .sln |
Microsoft Visual Studio Solution File |
| .swift |
Swift Source Code File |
| .src |
Source Code |
| .scm |
StarCraft Map File |