| .rec |
Topfield PVR Recording |
| .ris |
Research Information Systems Citation File |
| .rpp |
REAPER Project File |
| .ruleset |
Visual Studio Code Analysis Rule Set File |
| .resources |
Visual Studio Resource File |
| .rpy |
Touhou Project Replay File |
| .rad |
Radar ViewPoint Radar Data |
| .rmd |
R Markdown File |
| .rat |
PICS Rating File |
| .rs |
Rust Source Code File |
| .rc2 |
Visual Studio Resources File |
| .resjson |
Windows JavaScript Resources File |
| .refresh |
Visual Studio Refresh File |
| .rpres |
R Presentation File |
| .rwt |
ReadWriteThink Timeline |
| .rvf |
RichView Format File |
| .rtx |
Rich Text Document |
| .reb |
REBOL Script File |
| .ref |
IDRISI Raster Image Reference File |
| .rbxs |
ROBLOX Script |
| .rtp |
Gromacs Residue Topology Parameter File |
| .rhistory |
R History File |
| .rwstyle |
RapidWeaver Style File |
| .rtttl |
Ring Tone Transfer Language File |