| .RAS | Remedy Entertainment | File di giochi | Remedy Archive System File | Audacity | Open Source |
| .RAV | Nevrona Designs | File di giochi | Rave Reports Project File | Rave Reports | Nevrona Designs |
| .RAW | Unknown Developer | File di giochi | Raw Image Data File | MacPhun ColorStrokes | Macphun |
| .RB | Larian Studios | File di giochi | Divinity: Original Sin Game Data | Divinity: Original Sin | Larian Studios |
| .RBJ | Marco Pontello | File di giochi | XRK Compiled Redcode Object File | Extra Redcode Kit | Open Source |
| .RBN | Richard Pavlicek | File di giochi | Richard’s Bridge Notation File | Unknown Software | Unknown Developer |
| .RBXL | Roblox Corporation | File di giochi | ROBLOX Location File | ROBLOX | Roblox Corporation |
| .RBXM | Roblox Corporation | File di giochi | ROBLOX Model | ROBLOX | Roblox Corporation |
| .RBZ | Trimble Inc. | File di giochi | SketchUp Plugin | SketchUp | Trimble Inc. |
| .RCC | Angus Johnson | File di giochi | Resource Script File | Microsoft Visual Studio | Microsoft Corporation |
| .RCS | RandomControl | File di giochi | RandomControl Scene File | RandomControl Fryrender | RandomControl |
| .RD2 | Codemasters | File di giochi | TOCA Race Driver 2 Saved Game File | TOCA Race Driver 2 | Codemasters |
| .RDA | Open Source | File di giochi | R Data File | R | The R Foundation |
| .REC | TOPFIELD Co., Ltd. | File di giochi | Topfield PVR Recording | Squared 5 MPEG Streamclip | Open Source |
| .REL | Nintendo | File di giochi | Relocatable Module File | Stage Switcher | Unknown Developer |
| .REP | Rockstar Games | File di giochi | Grand Theft Auto Replay File | Grand Theft Auto III | Rockstar Games |
| .RES | Valve | File di giochi | Valve Resource File | Half-Life | Valve |
| .RESOURCES | Microsoft Corporation | File di giochi | Microsoft Visual Studio Resource | Microsoft Visual Studio | Microsoft Corporation |
| .REZ | Monolith Productions | File di giochi | Lithtech Game Engine Resource File | Dragon UnPACKer | Open Source |
| .RFA | Autodesk, Inc. | File di giochi | Revit Family File | AutoCAD Architecture | Autodesk, Inc. |
| .RFD | Recogniform Technologies | File di giochi | Recogniform Form Designer File | Recogniform | Recogniform Technologies |
| .RFM | Beatnik | File di giochi | Rich Music Format File | Unknown Software | Unknown Developer |
| .RGD | Redbeet Interactive | File di giochi | Raft Saved Game File | Raft | Redbeet Interactive |
| .RGI | RealNetworks | File di giochi | RealArcade Game Installer | RealArcade | RealNetworks |
| .RGM | Relic Entertainment | File di giochi | Essence Game Engine Model File | Warhammer 40K Dawn of War | Relic Entertainment |
| .RGP | RealNetworks | File di giochi | RealArcade Game Package | RealArcade | RealNetworks |
| .RGT | Relic Entertainment | File di giochi | Relic Entertainment Game Texture File | Corsix's Mod Studio | Open Source |
| .RIM | BioWare | File di giochi | BioWare Resource Image File | BioWare Neverwinter Nights | BioWare |
| .RKP | Devolutions | File di giochi | RemoteKeys Profile File | Remote Desktop Manager | Devolutions |
| .RKV | Krome Studios | File di giochi | Star Wars The Clone Wars Republic Heroes Game Archive File | Star Wars: The Clone Wars-- Republic Heroes | Krome Studios |
| .RL | R.LAB | File di giochi | R.viewer List File | R.viewer | R.LAB |
| .RME | Square Enix | File di giochi | Final Fantasy Audio Data | Final Fantasy XI | Square Enix |
| .RMF | Valve | File di giochi | Hammer Rich Map Format | Valve Hammer Editor | Valve |
| .RMO | Iron Crown Enterprises | File di giochi | Rolemaster Character Data | Rolemaster | Iron Crown Enterprises |
| .ROD | RIB Software | File di giochi | RIB Office Database File | RIB office | RIB Software |
| .ROS | Jon Taylor | File di giochi | BattleScribe Roster Editor File | BattleScribe | Jon Taylor |
| .ROT | Sierra Entertainment | File di giochi | Homeworld 2 Graphics File | Homeworld 2 | Sierra Entertainment |
| .RP2 | Cloanto Corporation | File di giochi | RetroPlatform Player Program Archive | Amiga Forever | Cloanto Corporation |
| .RPF | Rockstar Games | File di giochi | Grand Theft Auto Data File | Grand Theft Auto IV | Rockstar Games |
| .RPL | Nabi Studios | File di giochi | Toribash Replay File | Toribash | Nabi Studios |
| .RPX | Cemu | File di giochi | Wii U Game | Cemu | Cemu |
| .RPY | Team Shanghai Alice | File di giochi | Touhou Project Replay File | Touhou Project | Team Shanghai Alice |
| .RPYC | Tom "PyTom" Rothamel | File di giochi | Ren'Py Compiled Script | Ren'Py | Tom "PyTom" Rothamel |
| .RRS | Electronic Arts | File di giochi | Road Rash Saved Game Position | Road Rash | Electronic Arts |
| .RSD | Rosetta Stone | File di giochi | Rosetta Stone Data File | Rosetta Stone Language Learning | Rosetta Stone |
| .RSG | Surreal Software | File di giochi | Drakan: Order Of The Flame File | Drakan: Order Of The Flame | Surreal Software |
| .RSH | Relic Entertainment | File di giochi | Warhammer 40,000 Texture | Warhammer 40K Dawn of War | Relic Entertainment |
| .RUN | Open Source | File di giochi | Linux Executable File | Linux | Open Source |
| .RVI | Eidos Interactive | File di giochi | Revenant Game Archive | Revenant | Cinematix Studios, Inc. |
| .RVM | Eidos Interactive | File di giochi | Revenant Game Archive | Revenant | Cinematix Studios, Inc. |
| .RVN | Cyan | File di giochi | Riven Saved Game | Riven | Cyan |
| .RVS | Eidos Interactive | File di giochi | Revenant Game Archive | Revenant | Cinematix Studios, Inc. |
| .RW | Open Source | File di giochi | BVE Trainsim Railway Definition File | CyberLink PowerDVD | CyberLink |
| .RWD | NRG Systems | File di giochi | NRG Raw Wind Data File | Symphonie Data Retriever | NRG Systems |
| .RWS | Ludeon Studios | File di giochi | RimWorld Game Save File | Ludeon Studios RimWorld | Ludeon Studios |
| .RX3 | EA Maxis | File di giochi | FIFA Texture File | FIFA 14 | EA Sports |
| .RXDATA | Kadokawa Corporation | File di giochi | RMXP Data File | Enterbrain RPG Maker XP (RMXP) | Kadokawa Corporation |
di 1 
