| File extension | Developer/Producer | File description |
|---|---|---|
| R file extension | Apple | Apple Xcode Core Rez Program Format |
| R*CH file extension | Bare Bones Software | BBEdit |
| R0 file extension | RARLAB | WinRAR Compressed Archive Format |
| R00 file extension | RARLAB | Split Multi-volume RAR Compressed File Archive (part 2) |
| R01 file extension | RARLAB | Split Multi-volume RAR Compressed File Archive (part 3) |
| R02 file extension | RARLAB | Split Multi-volume RAR Compressed File Archive (part 4) |
| R03 file extension | RARLAB | Split Multi-volume RAR Compressed File Archive (part 5) |
| R04 file extension | Eugene Roshal | Split Multi-volume RAR Compressed File Archive (part 6) |
| R05 file extension | Eugene Roshal | Split Multi-volume RAR Compressed File Archive (part 7) |
| R06 file extension | Eugene Roshal | Split Multi-volume RAR Compressed File Archive (part 8) |
| R07 file extension | Eugene Roshal | Split Multi-volume RAR Compressed File Archive (part 9) |
| R08 file extension | Eugene Roshal | Split Multi-volume RAR Compressed File Archive (part 10) |
| R09 file extension | Eugene Roshal | Split Multi-volume RAR Compressed File Archive (part 11) |
| R0F file extension | RingCentral, Inc. | RingCentral Fax Document |
| R1 file extension | RARLAB | WinRAR Multi-Volume Archive Part 1 |
| R10 file extension | Eugene Roshal | Split Multi-volume RAR Compressed File Archive (part 12) |
| R11 file extension | Symantec Corporation | Norton Ghost Rar |
| R12 file extension | Symantec Corporation | Norton Ghost Rar |
| R13 file extension | Symantec Corporation | Norton Ghost Rar |
| R14 file extension | Symantec Corporation | Norton Ghost Rar |
| R15 file extension | Symantec Corporation | Norton Ghost Rar |
| R16 file extension | Symantec Corporation | Norton Ghost Rar |
| R17 file extension | Symantec Corporation | Norton Ghost Rar |
| R18 file extension | Symantec Corporation | Norton Ghost Rar |
| R19 file extension | Symantec Corporation | Norton Ghost Rar |
| R1M file extension | RealNetworks | RealOne Streaming Media Format |
| R1W file extension | Attachmate Corporation | Reflection Setting |
| R2 file extension | RARLAB | WinRAR Multi-Volume Archive Part 2 |
| R20 file extension | Symantec Corporation | Norton Ghost Rar |
| R21 file extension | Eugene Roshal | Split Multi-volume RAR Compressed File Archive (part 23) |
| R22 file extension | Symantec Corporation | Norton Ghost Rar |
| R23 file extension | Symantec Corporation | Norton Ghost Rar |
| R24 file extension | Symantec Corporation | Norton Ghost Rar |
| R25 file extension | Symantec Corporation | Norton Ghost Rar |
| R26 file extension | Symantec Corporation | Norton Ghost Rar |
| R27 file extension | N/A | Norton Ghost Rar |
| R28 file extension | Eugene Roshal | Split Multi-volume RAR Compressed File Archive (part 30) |
| R29 file extension | Eugene Roshal | Split Multi-volume RAR Compressed File Archive (part 31) |
| R2D file extension | RISA Technologies, LLC. | RISA-2D |
| R2K file extension | N/A | Repertoire 2000 Music Database |
| R2W file extension | Attachmate Corporation | Reflection Settings |
| R30 file extension | Eugene Roshal | Split Multi-volume RAR Compressed File Archive (part 32) |
| R31 file extension | Eugene Roshal | Split Multi-volume RAR Compressed File Archive (part 33) |
| R32 file extension | Eugene Roshal | Split Multi-volume RAR Compressed File Archive (part 34) |
| R33 file extension | Eugene Roshal | Split Multi-volume RAR Compressed File Archive (part 35) |
| R34 file extension | Eugene Roshal | Split Multi-volume RAR Compressed File Archive (part 36) |
| R35 file extension | Eugene Roshal | Split Multi-volume RAR Compressed File Archive (part 37) |
| R36 file extension | Eugene Roshal | Split Multi-volume RAR Compressed File Archive (part 38) |
| R37 file extension | Eugene Roshal | Split Multi-volume RAR Compressed File Archive (part 39) |
| R38 file extension | Eugene Roshal | Split Multi-volume RAR Compressed File Archive (part 40) |
| R39 file extension | Eugene Roshal | Split Multi-volume RAR Compressed File Archive (part 41) |
| R3D file extension | RED | REDCODE Multimedia Format |
| R3T file extension | RealNetworks, Inc. | RealNetworks RealText |
| R40 file extension | Eugene Roshal | Split Multi-volume RAR Compressed File Archive (part 42) |
| R41 file extension | Eugene Roshal | Split Multi-volume RAR Compressed File Archive (part 43) |
| R42 file extension | Eugene Roshal | Split Multi-volume RAR Compressed File Archive (part 44) |
| R43 file extension | Eugene Roshal | Split Multi-volume RAR Compressed File Archive (part 45) |
| R44 file extension | Eugene Roshal | Split Multi-volume RAR Compressed File Archive (part 46) |
| R45 file extension | Eugene Roshal | Split Multi-volume RAR Compressed File Archive (part 47) |
| R46 file extension | Eugene Roshal | Split Multi-volume RAR Compressed File Archive (part 48) |
| R47 file extension | Eugene Roshal | Split Multi-volume RAR Compressed File Archive (part 49) |
| R48 file extension | Eugene Roshal | Split Multi-volume RAR Compressed File Archive (part 50) |
| R49 file extension | Eugene Roshal | Split Multi-volume RAR Compressed File Archive (part 51) |
| R50 file extension | Eugene Roshal | Split Multi-volume RAR Compressed File Archive (part 52) |
| R51 file extension | Eugene Roshal | RAR Compressed Files From A Multi-volume Archive |
| R52 file extension | Eugene Roshal | RAR Compressed Files From A Multi-volume Archive |
| R53 file extension | N/A | RAR Compressed Files From A Multi-volume Archive |
| R54 file extension | Eugene Roshal | RAR Compressed Files From A Multi-volume Archive |
| R55 file extension | Eugene Roshal | RAR Compressed Files From A Multi-volume Archive |
| R56 file extension | Eugene Roshal | RAR Compressed Files From A Multi-volume Archive |
| R57 file extension | Eugene Roshal | RAR Compressed Files From A Multi-volume Archive |
| R58 file extension | Eugene Roshal | RAR Compressed Files From A Multi-volume Archive |
| R59 file extension | N/A | RAR Compressed Files From A Multi-volume Archive |
| R60 file extension | N/A | RAR Compressed Files From A Multi-volume Archive |
| R61 file extension | Eugene Roshal | RAR Compressed Files From A Multi-volume Archive |
| R62 file extension | Eugene Roshal | RAR Compressed Files From A Multi-volume Archive |
| R63 file extension | Eugene Roshal | RAR Compressed Files From A Multi-volume Archive |
| R64 file extension | N/A | RAR Compressed Files From A Multi-volume Archive |
| R65 file extension | Eugene Roshal | RAR Compressed Files From A Multi-volume Archive |
| R66 file extension | Eugene Roshal | RAR Compressed Files From A Multi-volume Archive |
| R67 file extension | Eugene Roshal | RAR Compressed Files From A Multi-volume Archive |
| R68 file extension | Eugene Roshal | RAR Compressed Files From A Multi-volume Archive |
| R69 file extension | Eugene Roshal | RAR Compressed Files From A Multi-volume Archive |
| R70 file extension | Eugene Roshal | RAR Compressed Files From A Multi-volume Archive |
| R71 file extension | Eugene Roshal | RAR Compressed Files From A Multi-volume Archive |
| R72 file extension | Eugene Roshal | RAR Compressed Files From A Multi-volume Archive |
| R73 file extension | Eugene Roshal | RAR Compressed Files From A Multi-volume Archive |
| R74 file extension | Eugene Roshal | RAR Compressed Files From A Multi-volume Archive |
| R75 file extension | Eugene Roshal | RAR Compressed Files From A Multi-volume Archive |
| R76 file extension | Eugene Roshal | RAR Compressed Files From A Multi-volume Archive |
| R77 file extension | Eugene Roshal | RAR Compressed Files From A Multi-volume Archive |
| R78 file extension | Eugene Roshal | RAR Compressed Files From A Multi-volume Archive |
| R79 file extension | Eugene Roshal | RAR Compressed Files From A Multi-volume Archive |
| R8 file extension | Microsoft Studios | Microsoft Flight Simulator Texture |
| R80 file extension | Eugene Roshal | RAR Compressed Files From A Multi-volume Archive |
| R81 file extension | N/A | RAR Compressed Files From A Multi-volume Archive |
| R82 file extension | Eugene Roshal | RAR Compressed Files From A Multi-volume Archive |
| R83 file extension | Eugene Roshal | RAR Compressed Files From A Multi-volume Archive |
| R84 file extension | Eugene Roshal | RAR Compressed Files From A Multi-volume Archive |
| R85 file extension | Eugene Roshal | RAR Compressed Files From A Multi-volume Archive |
| R86 file extension | Eugene Roshal | RAR Compressed Files From A Multi-volume Archive |
| R87 file extension | Eugene Roshal | RAR Compressed Files From A Multi-volume Archive |
| R88 file extension | Eugene Roshal | RAR Compressed Files From A Multi-volume Archive |
| R89 file extension | Eugene Roshal | RAR Compressed Files From A Multi-volume Archive |
| R8? file extension | N/A | Microsoft Word For DOS Font |
| R90 file extension | Eugene Roshal | RAR Compressed Files From A Multi-volume Archive |
| R91 file extension | Eugene Roshal | RAR Compressed Files From A Multi-volume Archive |
| R92 file extension | Eugene Roshal | RAR Compressed Files From A Multi-volume Archive |
| R93 file extension | Eugene Roshal | RAR Compressed Files From A Multi-volume Archive |
| R94 file extension | Eugene Roshal | RAR Compressed Files From A Multi-volume Archive |
| R95 file extension | N/A | RAR Compressed Files From A Multi-volume Archive |
| R96 file extension | Eugene Roshal | RAR Compressed Files From A Multi-volume Archive |
| R97 file extension | Eugene Roshal | RAR Compressed Files From A Multi-volume Archive |
| R98 file extension | N/A | RAR Compressed Files From A Multi-volume Archive |
| R99 file extension | Eugene Roshal | RAR Compressed Files From A Multi-volume Archive |
| RA file extension | RealNetworks | RealAudio Audio Format |
| RA2 file extension | N/A | Flare RAW |
| RA3AUTOSAVE file extension | Electronic Arts, Inc. | Command & Conquer Red Alert 3 Save Game |
| RA3CAMPAIGN file extension | Electronic Arts, Inc. | Command & Conquer Red Alert 3 Save Game |
| RA3REPLAY file extension | Electronic Arts, Inc. | Command & Conquer: Red Alert 3 Replay |
| RA3SKIRMISH file extension | Electronic Arts, Inc. | Command & Conquer: Red Alert 3 Skirmish Map |
| RAC file extension | Concept2 Inc. | Venue Race Application |
| RAD file extension | N/A | Radar ViewPoint Radar Data Format |
| RADIUMKEY2 file extension | CatPig Studios | Radium Registration Format |
| RADIUS file extension | N/A | Ruby-Radius Scipt |
| RADQ file extension | RadicalPlay.com | Need For Madness Game Archive |
| RAE file extension | Schlichtherle IT Services | TrueZIP Encrypted ZIP Archive |
| RAES file extension | Schlichtherle IT Services | TrueZIP Encrypted ZIP Archive |
| RAF file extension | Fuji | Fuji CCD-RAW Graphic Format |
| RAG file extension | Bentley Systems, Incorporated | RAM Advanse Generator |
| RAI file extension | Astronomical Institute of the Academy of Sciences of the Czech Republic | SPEFO |
| RAKE file extension | Ruby community | Ruby Makefile |
| RAKEFILE file extension | Ruby community | Ruby Makefile |
| RAL file extension | Span Software | WinRail Track Design Format |
| RAM file extension | RealNetworks | Real Audio Metafile |
| RAMD file extension | Apple, Inc. | Repeat After Me Document |
| RAN file extension | Owen F Ransen | Dexterpen |
| RAP file extension | MAGIX AG | Magix Music Studio Rap |
| RAPC file extension | BlackBerry (Research In Motion Limited) | Java 2 ME Unit |
| RAR file extension | Eugene Roshal | WinRAR RAR Compressed Archive |
| RAR1 file extension | N/A | RAR Archive |
| RAR5 file extension | RARLAB | WinRAR 5 Compressed Archive Format |
| RARENX file extension | Egis Technology Inc. | Egis Encrypted RAR |
| RARX file extension | N/A | Renamed RAR |
| RAS file extension | Sun Microsystems | Sun Raster Bitmap Format |
| RASKINLICENSE file extension | Raskin Software | Raskin For Mac License Format |
| RASKINPLACE file extension | Raskin Software | Raskin Place Settings Format |
| RAST file extension | N/A | Sun Raster Bitmap Image |
| RAT file extension | W3C | PICS Platform For Internet Content Selection Format |
| RATDVD file extension | ACE GmbH | RatDVD Commpressed DVD Movie |
| RAV file extension | Nevrona Designs | Rave Reports Project Format |
| RAW file extension | N/A | Digital Camera Photo RAW Image Format |
| RAX file extension | RealNetworks | RealMedia Streaming Format |
| RAY file extension | Craig Kolb | Rayshade Picture Image Format |
| RA_ file extension | Resco, s.r.o. | Resco Photo Viewer Thumbnail Cache |
| RB file extension | N/A | Ruby Script Format |
| RB0 file extension | Trend Micro Inc. | Trend AntiVirus Backup |
| RB1 file extension | R:BASE Technologies, Inc. | R:Base Data Format |
| RB2 file extension | R:BASE Technologies, Inc. | R:Base Data Format |
| RB3 file extension | R:BASE Technologies, Inc. | R:BASE Data |
| RB4 file extension | Sarm Software | Resume Builder Data Format |
| RBA file extension | Just Great Software Co. Ltd. | RegexBuddy Regular Expression |
| RBB file extension | TAN$TAAFL Software Company | Top Secret Crypto Gold Random Bits Bin |
| RBC file extension | EMC Insignia | Roxio Retrospect Backup Catalogue Format |
| RBDF file extension | N/A | Reading For The Blind And Dyslexic Audio Book With Text |
| RBF file extension | EMC Insignia | Roxio Retrospect Backup Format |
| RBG file extension | Just Great Software Co. Ltd. | RegexBuddy GREP Action |
| RBI file extension | Robert Bentley, Inc. | EBahn Reader |
| RBJ file extension | Marco Pontello | Extra Redcode Kit Compiled Redcode Object Format |
| RBK file extension | Microsoft | Microsoft Windows 95 Registry Backup Format |
| RBL file extension | Just Great Software Co. Ltd. | RegexBuddy Library |
| RBM file extension | Propellerhead Software AB | Propellerhead ReBirth Modulation V2.0 |
| RBO file extension | REAL Software, Inc. | REALbasic Class |
| RBP file extension | REAL | REALbasic Project Format |
| RBS file extension | N/A | Rebirth Song Format |
| RBT file extension | LEGO | Lego MINDSTORMS NXT Program Format |
| RBTX file extension | N/A | NXT Create Pack & Go Package |
| RBVCP file extension | REAL Software | Real Studio Project Format |
| RBW file extension | N/A | Ruby |
| RBX file extension | IBM | IBM Rembo-C Compiled Script Format |
| RBXL file extension | ROBLOX | ROBLOX Game Format |
| RBXM file extension | ROBLOX | ROBLOX Model Format |
| RBXS file extension | ROBLOX | ROBLOX Script |
| RBZ file extension | Trimble | SketchUp Extension |
| RC file extension | N/A | Microsoft Visual Studio Visual C/C++ Resource Script Format |
| RC1 file extension | Samsung | Samsung S5230 Firmware Format |
| RC2 file extension | Microsoft | Microsoft Visual Studio Visual C/C++ Non-compilable Resource Script Format |
| RC3 file extension | Microsoft Corporation | Visual C Resource |
| RCB file extension | RealityRipple.com | Ripple Chat Bot Document |
| RCD file extension | University of Virginia | Arcade Input Format |
| RCF file extension | SonicWALL | SonicWALL VPN Configuration Format |
| RCG file extension | Recog | Recog Character Recognition Set Format |
| RCH file extension | Grassland, Soil & Water Research Laboratory | SWAT Reach Output |
| RCL file extension | Roxio | Easy CD And DVD Creator Project Format |
| RCN file extension | Qstarz International Co, Ltd. | QRacing Track |
| RCO file extension | Sony | Sony PlayStation Portable PSP Resource Format |
| RCP file extension | Pacific Software | Rich Chart Builder Project |
| RCPROJECT file extension | Apple | IMovie Project Format |
| RCS file extension | RandomControl | RandomControl Scene Format |
| RCT file extension | Microsoft | Microsoft Visual Studio Resource Template Format |
| RCU file extension | RealWorld Graphics | RealWorld Layered Cursor Image |
| RCV file extension | QUALCOMM Incorporated | Eudora Temporary Download |
| RCX file extension | RED | REDCINE-X Project Format |
| RCY file extension | Propellerhead Software | ReCycle Audio Loop Format |
| RD file extension | N/A | R Document |
| RD2 file extension | Codemasters | TOCA Race Driver 2 Saved Game |
| RD3 file extension | Corel Corporation | CorelDRAW CorelDream 3D |
| RD3F file extension | Corel Corporation | CorelDRAW CorelDream 3D |
| RD5 file extension | Autodesk, Inc. | Autodesk Road Aligment |
| RDA file extension | The R Project for Statistical Computing | Oracle Storage Area Format |
| RDAT file extension | N/A | RNA Data (RDAT) |
| RDATA file extension | The R Project for Statistical Computing | R Workspace Format |
| RDB file extension | N/A | N64 Nintendo 64 ROM Database Format |
| RDC file extension | Clark Labs | IDRISI Raster Documentation Format |
| RDD file extension | ReliaSoft Corporation | ALTA |
| RDE file extension | Mindware Studios, s.r.o. | Painkiller Overdose Game |
| RDF file extension | N/A | Resource Description Framework RSS Feed Format |
| RDG file extension | TechSmith Corporation | Morae Recorded Video |
| RDI file extension | Blue Mist Injector | Red Dragon ISecure Settings Format |
| RDL file extension | Bentley Systems | Bentley MicroStation Redline Format |
| RDLC file extension | Microsoft | Microsoft Visual Studio Report Definition Format |
| RDLX file extension | Microsoft | Microsoft Power View Project Format |
| RDM file extension | Matteo Guarnieri | Ragdoll Masters Preference |
| RDO file extension | N/A | Xerox Rawster Document Object Format |
| RDOC file extension | James Britt | RubyDoc Script |
| RDP file extension | Microsoft | Microsoft Windows Remote Desktop Connection Settings Format |
| RDS file extension | DAZ Productions | Ray Dream 3D Animation Format |
| RDT file extension | Adobe Systems Incorporated | Adobe Captivate RoboDemo Template |
| RDV file extension | Nikolai Teofilov | NTgraph |
| RDW file extension | www.MediaChance.com | Real-DRAW Project |
| RDX file extension | Borland | Borland Reflex Database Format |
| RDY file extension | Teldas GmbH | INet-Server |
| RDZ file extension | MMIX Mandriva | Mandrake Linux Install |
| RE file extension | N/A | Python Regular Expressions Source Code |
| RE2 file extension | Argonne National Laboratory | NEK5000 Mesh |
| RE4 file extension | Capcom Co., Ltd. | Resident Evil 4 |
| REA file extension | N/A | Readme Text |
| REAL file extension | The GNOME Project | Gnome Desktop |
| REAPEAKS file extension | Cockos Incorporated | REAPER Scratch |
| REB file extension | REBOL Technologies | REBOL Script Format |
| REC file extension | Topfield | Recorded Format |
| RECO file extension | Evernote Corporation | Evernote |
| RECORD file extension | DaveTech | Recorded Audio Format |
| RED file extension | Tailor Made Software | CADViewer Redline Markup Format |
| REDIR file extension | Spotify | Spotify Redirect Format |
| REF file extension | Microsoft | Reference Format |
| REFERENCE file extension | N/A | Budget In Brief Application Reference Format |
| REFI file extension | Rick Meyers | E-Sword Reference IOS Notes |
| REFRESH file extension | Microsoft | Microsoft Visual Studio Refresh Format |
| REFX file extension | Rick Meyers | E-Sword Reference Library Note |
| REG file extension | Microsoft | Windows Registry Data Format |
| REGI file extension | Kagi | Kagi Registration Module |
| REGS file extension | AOL Inc. | Netscape Registry |
| REGTRANS-MS file extension | Microsoft | Microsoft Windows Vista And Windows 7 Registry Format |
| REGULARIZER file extension | Richard Hughey - Kevin Karplus - Anders Krogh | SAM Transition Regularizer |
| REJ file extension | N/A | Mercurial Reject |
| REL file extension | Symantec | Norton Internet Security 2001 Log Format |
| RELOC file extension | Microsoft | Microsoft Windows EXE Relocation Format |
| RELS file extension | Microsoft | Microsoft Open Office XML Relationships Format |
| REM file extension | Research In Motion | BlackBerry Encrypted Data Format |
| RENDERMAN file extension | Pixar | Pixar RenderMan 3.1 Specification |
| REP file extension | Rockstar Games | Game Replay Format |
| REPATCH file extension | Propellerhead Software AB | Reason DCAM EnvShaper Effect Preset |
| REPX file extension | Developer Express Inc. | XtraReports Report Definition |
| REQ file extension | N/A | SSL Certificate Request Format |
| RES file extension | Borland | Microsoft C, C++ Compiled Resource Format |
| RESDEX file extension | Firefly Studios Ltd. | Stronghold 3 Resource |
| RESJSON file extension | Microsoft | Microsoft Windows 8 Metro JavaScript Format |
| RESMONCFG file extension | Microsoft | Microsoft Windows Resource Monitor Settings Format |
| RESOURCECONFIG file extension | Microsoft Corporation | Visual Studio Resource Configuration |
| RESOURCES file extension | Microsoft | Microsoft Visual Studio Resource Format |
| RESP file extension | Microsoft Corporation | Microsoft Windows Report Log |
| REST file extension | N/A | ReStructuredText |
| RESW file extension | Microsoft | Microsoft Windows 8 Resources Format |
| RESX file extension | Microsoft | Microsoft Visual Studio .NET XML Resource Template Format |
| RET file extension | SAP | SAP BusinessObjects Template Format |
| REV file extension | RARLAB | WinRAR Recovery Volume Format |
| REW file extension | RWTH Aachen University | MRMC Markov Reward Model Checker Definition |
| REWI file extension | RWTH Aachen University | MRMC Markov Reward Model Checker Definition |
| REX file extension | Propellerhead Software | ReCycle Audio Loop Export Format |
| REZ file extension | Monolith | LithTech Game Engine Resource Format |
| RF file extension | Sun Microsystems, Inc. | Sun Bitmap Image |
| RF0 file extension | SmartWare Corporation | SmartWare Runtime Project |
| RF1 file extension | N/A | Retirement Forecast Format |
| RF2 file extension | SmartWare Corporation | SmartWare Runtime Project |
| RF3 file extension | SmartWare Corporation | SmartWare Runtime Project |
| RF4 file extension | SmartWare Corporation | SmartWare Runtime Project |
| RF5 file extension | Tektronix, Inc. | Tektronix |
| RFA file extension | Autodesk | Autodesk Revit Architecture Family Format |
| RFB file extension | Siber Systems | RoboForm Bookmarks Format |
| RFC file extension | Siber Systems | RoboForm Contact Format |
| RFD file extension | Recogniform Technologies | RecogniFORM Form Definition Format |
| RFE file extension | Institute of Fluid Mechanics and Environmental Physics in Civil Engineering | RockFlow Log |
| RFG file extension | Raddon Financial Group | RFG Integrator System Database |
| RFGS_PC file extension | Volition | Red Faction: Guerilla Saved Game Format |
| RFH file extension | Raddon Financial Group | RFG Integrator Householding Database |
| RFI file extension | Astronomical Institute of the Academy of Sciences of the Czech Republic | SPEFO Stellar Spectra Analysis |
| RFL file extension | Propellerhead Software | Reason Sound Bank |
| RFM file extension | Image Space | RFactor Modification Format |
| RFMOD file extension | N/A | RFactor 2 Mod |
| RFN file extension | Siber Systems | RoboForm SafeNote Files |
| RFO file extension | Siber Systems | RoboForm License And Options Format |
| RFP file extension | Siber Systems | RoboForm Passcard Format |
| RFQ file extension | Siber Systems | RoboForm SearchCard Format |
| RFR file extension | Adobe Systems Incorporated | Adobe Photoshop Frame Filter |
| RFS file extension | Next Limit Technologies | RealFlow Script |
| RFT file extension | Autodesk | Revit Template Format |
| RFV file extension | N/A | Restricted Focus Viewer Input |
| RFW file extension | Fuzhou Rockchip Electronics | Rockchip Firmware Format |
| RFX file extension | Siber Systems, Inc. | RoboForm Blocked Passcard |
| RG file extension | Chris Cannam and D. Michael McIntyre | Rosegarden Music |
| RGB file extension | SGI | SGI RGB Bitmap Format |
| RGBA file extension | N/A | Silicon Graphics Image File Format |
| RGBE file extension | N/A | Radiance Map |
| RGD file extension | Chris Cannam and D. Michael McIntyre | Rosegarden Device Definition |
| RGDB file extension | N/A | Adobe Registration Database |
| RGE file extension | Microsoft | Microsoft Outlook For Mac Archive Format, Entourage Personal Folder Format |
| RGF file extension | ElcomSoft Co. Ltd. | Advanced Registry Tracer Scan Data |
| RGH file extension | N/A | ZZ RouGH Image |
| RGI file extension | RealNetworks, Inc. | RealArcade Game Installer |
| RGM file extension | Relic Entertainment Inc. | Essence Game Engine Model |
| RGMB file extension | RootsMagic | RootsMagic Backup Format |
| RGMC file extension | RootsMagic | RootsMagic Genealogy Project Format |
| RGN file extension | Garmin | Garmin Region Format |
| RGO file extension | Cerience | RepliGo Virtual Print Format |
| RGP file extension | N/A | RealArcade Game Package |
| RGRP file extension | Avid Technology | Pro Tools Region Group Format |
| RGS file extension | N/A | InstallShield Script For Windows Registry |
| RGSS2A file extension | Enterbrain | RPG Maker VX RGSS Encrypted Archive Format |
| RGSS3A file extension | Enterbrain, Inc. | RPG Maker VX RGSS Version 3 Encrypted Archive |
| RGSSAD file extension | Enterbrain, Inc. | RPG Maker VX RGSS Encrypted Archive |
| RGU file extension | Microsoft Corporation | Microsoft Windows Mobile Registry Entry |
| RGUNINST file extension | RealNetworks, Inc. | RealArcade Uninstall Script |
| RGZ file extension | Gravity Interactive Inc. | Ragnarok EXE And BGM Patch Archive |
| RH file extension | Microsoft Corporation | C++ Resource Header |
| RHA file extension | Adobe Systems Incorporated | Adobe RoboHelp AIR Help Project |
| RHISTORY file extension | The R Project for Statistical Computing | R History Format |
| RHK file extension | N/A | Backdoor.Win32.Rbot.rhk Trojan Virus |
| RHL file extension | Edge Sounds, LLC | EdgeSounds RatHole Compressed Audio |
| RHM file extension | Right Hemisphere Inc. | Right Hemisphere Material |
| RHP file extension | N/A | Rhino 3D Plug-in Format |
| RHTML file extension | N/A | Ruby HTML Web Page Format |
| RI file extension | IBM | Lotus 1-2-3 Data |
| RIBBONS file extension | M.Carson | Ribbons |
| RIC file extension | The LEGO Group | Lego NXT Image Format |
| RID file extension | BronzeWare Inc. | GerbMagic Raster Image |
| RIF file extension | Corel | Corel Painter Raster Image Format |
| RIFF file extension | Corel | Painter Raster Image |
| RIG file extension | Iterum | VRigger Design Format |
| RIK file extension | N/A | SharpMap |
| RIM file extension | BioWare | BioWare Resource Image Format |
| RIO file extension | IBM | IBM AIX System |
| RIP file extension | Hit'n'Mix | Hit’n’Mix Audio Format |
| RIPXR file extension | RipXR Corp. | RipXR Compressed Archive |
| RIS file extension | Research Information Systems | Research Information Systems Citation Format |
| RISCOS file extension | RISCOS Ltd. | Acorn RISC OS |
| RISE file extension | RISE to Bloome Software | RISE Information Model Format |
| RIV file extension | School of Aquatic & Fishery Sciences, University of Washington | CRiSP Harvest |
| RIX file extension | RIX Softworks | ColoRIX Bitmap Image |
| RJS file extension | N/A | Ruby JavaScript Source Code Format |
| RJT file extension | RealNetworks, Inc. | RealPlayer Track Info Style |
| RK file extension | M Software | WinRK Archive Format |
| RKC file extension | Nintendo Co., Ltd. | Mario Kart Wii Competition Data |
| RKG file extension | Nintendo Co., Ltd. | Mario Kart Wii Ghost Data |
| RKP file extension | Rockchip | Rockchip MP4 Player Game |
| RKR file extension | SourceForge.net | Rakarrack |
| RKT file extension | N/A | Racket Information Module |
| RKV file extension | Krome Studios | Star Wars The Clone Wars Republic Heroes Game Archive |
| RKW file extension | RockWare, Inc. | RockWorks Graphics |
| RL file extension | R.LAB | R.viewer Format |
| RL1 file extension | Interplay Entertainment Corporation | Descent 1 Registered Level |
| RL2 file extension | Interplay Entertainment Corporation | Descent 2 Registered Level |
| RL4 file extension | N/A | Device-independent Bitmap |
| RLA file extension | N/A | Alias/Wavefront Bitmap Image |
| RLB file extension | N/A | Alias/Wavefront Bitmap Image |
| RLC file extension | Esri | ArcView Image |
| RLD file extension | Symantec Corporation | Norton Commander Temporary |
| RLE file extension | N/A | Run Length Encoded Bitmap |
| RLEGZ file extension | Golly | Golly Compressed Pattern Format |
| RLF file extension | ESRI | ArcGIS Report Layout Format |
| RLG file extension | ReliaSoft Corporation | Weibull++ |
| RLI file extension | RealWorld Graphics | RealWorld Graphics Layered Image |
| RLL file extension | Microsoft | Resource Hacker Resource Library Format |
| RLN file extension | Alpha Software, Inc. | Alpha Four Database |
| RLOG file extension | N/A | MPICH Log |
| RLS file extension | Nokia | Symbian Localization Format |
| RLST file extension | Electronic Arts, Inc. | Sims 3 Data |
| RLT file extension | ReliaSoft Corporation | ReliaSoft BlockSim & Weibull++ |
| RLW file extension | Reflexive® Entertainment Inc. | Ricochet Lost Worlds: Recharged |
| RLX file extension | JustSystems Corp. | XMetaL Compiled Form |
| RM file extension | RealNetworks | RealMedia Format |
| RM3D file extension | MSCI Inc. | RiskMetrics RiskManager |
| RMA file extension | RealNetworks, Inc. | RealMedia Audio |
| RMAN file extension | Oracle Corporation | Oracle Datafile Backup |
| RMAP file extension | CompeGPS TEAM S.L. | CompeGPS Land Raster Map |
| RMB file extension | Utimaco Safeware AG | SafeGuard RemovableMedia Keyring Backup |
| RMBAK file extension | PC Tools | Registry Mechanic Backup Format |
| RMC file extension | Washington State Department of Transportation | RMCalc |
| RMD file extension | RealNetworks | RealPlayer Media Format |
| RMDP file extension | Microsoft Studios | Alan Wake Game Data |
| RME file extension | SQUARE ENIX CO. | Final Fantasy Audio |
| RMF file extension | N/A | Beatnik Rich Music Format |
| RMG file extension | N/A | Rimage Image |
| RMGC file extension | RootsMagic, Inc. | RootsMagic Genealogy Database |
| RMI file extension | N/A | MIDI-sequention Music (RIFF RMID Format) |
| RMID file extension | N/A | RIFF RMID Midi Format |
| RMJ file extension | RealNetworks | RealAudio Media Format |
| RMK file extension | Grafx Software Development Tools | CA Clipper RMake Makefile |
| RML file extension | Autodesk | Redline Markup Language Format |
| RMM file extension | RealNetworks | RAM Meta Format |
| RMN file extension | Oracle Corporation | Oracle Recovery Manager Script |
| RMP file extension | RealNetworks | RealAudio Audio Format |
| RMR file extension | Individual Software | ResumeMaker Format |
| RMS file extension | RealNetworks | RealMedia Secure Media File Format |
| RMSKIN file extension | The Rainmeter Team | Rainmeter Skin Format |
| RMT file extension | N/A | Linksys Router Firmware Format |
| RMUF file extension | Alpha Software | Alpha Five Runtime Format |
| RMV file extension | Radical Entertainment | The Simpsons Hit & Run Video Format |
| RMVB file extension | RealNetworks | RealMedia Variable Bitrate Format |
| RMW file extension | ALD | RAM Commander Database |
| RMX file extension | N/A | RealMedia Secure Media Clip |
| RNA file extension | Logotron Ltd. | Revelation Natural Art Document |
| RNC file extension | N/A | RELAX NG Compact Syntax Format |
| RND file extension | PGP | PGP (Pretty Good Privacy) Random Seed |
| RNG file extension | N/A | Nokia Communicator Ringing Tone Format |
| RNK file extension | Microsoft Corporation | Dial-up Shortcut |
| RNL file extension | N/A | GTX Runlength Encoded Bitmap Graphics |
| RNQ file extension | N/A | Renque Model Format |
| RNR file extension | Trilobyte, Inc. | The 11th Hour Game Data |
| RNS file extension | Propellerhead Software | Reason Audio Format |
| RNT file extension | Planit | EdgeCAM Licensing Data |
| RNW file extension | N/A | Sweave Source |
| RNX file extension | RealNetworks | RealPlayer Audio Or Settings Format |
| RO file extension | Procedimientos-Uno, S.L. | ROwin Project |
| ROACJ file extension | Ubisoft Entertainment S.A. | Call Of Juarez Game Resource Data |
| ROB file extension | Taskware | Wintask Compiled Program |
| ROBO file extension | Arvid Halma | RoboMind Source Code |
| ROC file extension | spacecad.com | SpaceCAD Rocket Design |
| ROCA file extension | RIB Software | RIB Office Compressed Archive Format |
| ROCK file extension | Rockbox | Rockbox Installation Format |
| ROCKWELL file extension | N/A | Rockwell (modem) |
| ROCKWELL-2 file extension | N/A | Rockwell 2-bit ADPCM Data |
| ROCKWELL-3 file extension | N/A | Rockwell 3-bit ADPCM Data |
| ROCKWELL-4 file extension | N/A | Rockwell 4-bit ADPCM Data |
| ROD file extension | Actuate | Actuate E.Report Designer Report Object Design |
| RODL file extension | RemObjects | RemObjects Definition Language Format |
| ROFF file extension | N/A | Unformatted Manual Page (Roff/nroff/troff/groff) |
| ROFL file extension | Riot Games Inc. | Leagues Of Legends Replay |
| ROG file extension | N/A | Roger 2 Data Format |
| ROH file extension | N/A | Avantes |
| ROI file extension | Actuate | Report Object Instance |
| ROL file extension | N/A | AdLib Visual Composer Music Data Format |
| ROM file extension | N/A | Read Only Memory Image (emulators/AONs) |
| ROO file extension | N/A | WinRAR Archive |
| ROQ file extension | Id Software | Id Software Game Video |
| ROS file extension | Jonathan Taylor | BattleScribe Data Format |
| ROT file extension | Sierra Entertainment | Homeworld 2 Game Graphics Data Format |
| ROTEST file extension | RemObjects | RemObjects SDK Test Format |
| ROTESTRESULT file extension | RemObjects | RemObjects SDK Test Results Format |
| ROU file extension | N/A | Gerber Route Format |
| ROV file extension | N/A | Actuate E.Report Designer Report Object Value |
| ROW file extension | Actuate Corporation | Actuate E.Report HTML Report Document |
| ROX file extension | Sonic Solutions | Roxio Creator Project Format |
| ROXIO file extension | Sonic Solutions | Roxio Creator Project Format |
| ROZ file extension | aSc Applied Software Consultants | ASc TimeTables Timetable |
| RP file extension | N/A | RealPix Image Format |
| RP2 file extension | Cloanto | RetroPlatform Player (Amiga Forever) Format |
| RP3 file extension | Electronic Arts, Inc. | Need For Speed Game |
| RP9 file extension | Cloanto | RetroPlatform Format |
| RPA file extension | RIB Software | RIB ITWO Project Archive Format |
| RPACK file extension | Ubisoft Entertainment S.A. | Call Of Juarez Game Data |
| RPB file extension | Famatech | Radmin Phonebook Format |
| RPBM file extension | N/A | Portable Bitmap Image |
| RPC file extension | The Sage Group plc | ACT! Report |
| RPD file extension | Hand Multimedia | Roleplay Designer Data Format |
| RPE file extension | XStream Software | Performance Analyzer |
| RPF file extension | N/A | 3ds Max Rich Pixel Format |
| RPG file extension | Christopher Matthews | The RPG Programming Language |
| RPGM file extension | N/A | Portable Greyscale Image |
| RPI file extension | N/A | Render Extension |
| RPJ file extension | Uni Comp | Real Pac Batch Job Format |
| RPK file extension | RadLight | RadLight Skin Format |
| RPL file extension | Nabi Studios | Toribash Replay Game Format |
| RPLIB file extension | Axure Software Solutions | Axure Widget Library Format |
| RPLN file extension | Adobe Systems Incorporated | Adobe InDesign Required Function Library |
| RPM file extension | Red Hat | Linux Package Manager Format |
| RPMSG file extension | Microsoft | Microsoft Restricted Permission Message Format |
| RPN file extension | The Sage Group plc | ACT! 2.0 Report |
| RPNM file extension | N/A | Portable Image Image |
| RPO file extension | IBM | IBM XL C/C++ For Linux Compiler |
| RPP file extension | Cockos | REAPER Project Format |
| RPPM file extension | N/A | Portable Image Image Format |
| RPPRJ file extension | Axure Software Solutions | Axure RP Shared Project Format |
| RPR file extension | IBM | IBM Voice Type Languages Vocabels |
| RPROFILE file extension | N/A | Quick-R R Programming Language Configuration |
| RPS file extension | Autodesk | 3D Studio Max Render Preset Settings Format |
| RPT file extension | SAP | Report Format |
| RPT2 file extension | eSignal | ESignal Report |
| RPTPROJ file extension | Microsoft Corporation | Microsoft Visual Studio 2008 Report Project |
| RPTR file extension | RafflePrinter.com | RafflePrinter Document Format |
| RPTX file extension | Spiceworks Inc. | Spiceworks Report |
| RPV file extension | RealNetworks, Inc. | RealPlayer Visualization |
| RPW file extension | N/A | RPWiz Project |
| RPX file extension | Geocentrix Ltd. | Repute Tutorial |
| RPY file extension | N/A | Python Script Format |
| RPYC file extension | Ren'Py | RenPy Game Engine Compiled Script Format |
| RPYM file extension | N/A | RenPy Module |
| RPZ file extension | SAP AG | Crystal Reports ZIP Compressed And Encrypted Report |
| RQC file extension | Micro Focus International plc | Micro Focus Revolve |
| RQI file extension | R-Quest Technologies, LLC | TrueNet R-Quest Disc Image |
| RQM file extension | N/A | IBM RequisitePro Metrics Report |
| RQT file extension | N/A | Report Quality Plotting Module |
| RQY file extension | Microsoft Corporation | Microsoft Excel OLE DB Query |
| RRA file extension | Iterum | VRigger Rigging Format |
| RRC file extension | BlackBerry (Research In Motion Limited) | BlackBerry Java Resource Content |
| RRD file extension | N/A | Reduced Resolution Dataset Format |
| RRD4J file extension | N/A | RRD4J Graph |
| RRF file extension | Raymarine UK Ltd | Raytech |
| RRG file extension | JRiver, Inc. | JRiver Media Center License |
| RRH file extension | BlackBerry (Research In Motion Limited) | BlackBerry Resource Header |
| RRI file extension | RealWorld Graphics | RealWorld Icon Editor Picture Image Format |
| RRPA file extension | Oracle Corporation | Oracle Reports Remote Printing Utility PDF Report |
| RRR file extension | PC Tools | Registry Mechanic Backup Format |
| RRT file extension | Alta Vente | Rhapzode Resource Template Format |
| RRX file extension | IBM | IBM Datacap Define |
| RS file extension | Utilant | RapidSketch Sketch Document Format |
| RS1 file extension | Natural Resources Canada | RETScreen Spreadsheet |
| RS2 file extension | RailSim2 | RailSim2 Layout Format |
| RS7 file extension | Synopsys, Inc. | LightTools Radiant Source Model |
| RS8 file extension | Radiant ZEMAX, LLC. | ProSource |
| RSA file extension | N/A | RSA Digital Certificate Format |
| RSB file extension | Ubisoft Entertainment | Red Storm Bitmap Format |
| RSC file extension | Nokia | Symbian Application Compiled Resource Format |
| RSD file extension | REAL | Database Format |
| RSD-JOURNAL file extension | N/A | REALSQLDatabase Journal |
| RSDB file extension | Resort Software Pty. Ltd. | Resort Software Database |
| RSDF file extension | RapidShare | RapidShare Download Settings Format |
| RSDS file extension | N/A | SharePoint Shared Data Source |
| RSED file extension | http://www.resedit.net/ | ResEdit |
| RSF file extension | Mediafour Corporation | Mediafour MacDrive Macintosh Resource Fork |
| RSFX file extension | Attachmate Corporation | Reflection |
| RSG file extension | Surreal Software, Inc. | Drakan Order Of The Flame |
| RSH file extension | Relic Entertainment Inc. | Warhammer 40,000 Texture |
| RSI file extension | Reactive Systems, Inc. | Reactis |
| RSL file extension | Corel Corporation | Corel Paradox Saved Form |
| RSM file extension | WinWay | WinWay Deluxe Resume Format |
| RSML file extension | RealNetworks, Inc. | RealPlayer ML |
| RSN file extension | Propellerhead | Propellerhead Reason Audio Format |
| RSO file extension | LEGO | LEGO NXT Brick Audio Format |
| RSP file extension | Rockwell Automation | RSLogix PLC Program Format |
| RSQ file extension | IBM | IBM 4690 Operating System |
| RSR file extension | Smith Micro | Poser Model Preview Format |
| RSRC file extension | N/A | MAC OS Resource Format |
| RSRS file extension | Magic Modules Pty Ltd | Buddy API |
| RSS file extension | N/A | Really Simple Syndication - RSS File Format |
| RST file extension | N/A | ReStructuredText Format |
| RSU file extension | Attachmate Corporation | Reflection For IBM Updated Settings |
| RSV file extension | Rockwell Automation | RSView32 Project Format |
| RSW file extension | N/A | R&R SQL Report Writer Report Format |
| RSX file extension | RED | RED Metadata XML Format |
| RSYM file extension | Graphisoft | ArchiCAD For Mac Geometric Description Language |
| RS_ file extension | Apple, Inc. | Macintosh Resource Fork |
| RT file extension | RealNetworks | RealText Subtitle Format |
| RT2 file extension | Des & Lorraine Newman | OziExplorerCE Route |
| RTA file extension | Adobe Systems | Adobe RoboHelp Configuration Format |
| RTAB file extension | N/A | Randy Tab Guitar Tablature |
| RTB file extension | Robert McNeel & Associates | Rhino 3D Toolbar Collection |
| RTC file extension | Microsoft | Microsoft Office Live Meeting Connection Format |
| RTD file extension | N/A | Ragtime Examples Render Format |
| RTE file extension | N/A | RTEncoder RTE Encoded Format |
| RTF file extension | N/A | Rich Text Format Document |
| RTFD file extension | N/A | Rich Text With Graphic Document Format |
| RTG file extension | Autodesk, Inc. | Autodesk Maya 3D Scene Data |
| RTH file extension | ANSYS Inc. | ANSYS Results |
| RTI file extension | N/A | Real Tracker Instrument Format |
| RTK file extension | Adobe Systems Incorporated | Adobe RoboHelp Configuration |
| RTKT file extension | GeoVisu Development Team | Royaltek Binary Data |
| RTL file extension | N/A | HP Raster Transfer Language Bitmap Image |
| RTM file extension | N/A | Real Tracker Music Module (MOD) Format |
| RTMAP file extension | CompeGPS TEAM S.L. | CompeGPS Land Raster Map |
| RTN file extension | Optical Gaging Products, Inc. | MeasureMind 3D |
| RTP file extension | N/A | TurboTax Update Format |
| RTPI file extension | N/A | 3rdTech Scanner |
| RTR file extension | Fantiusen Software | Astrotite 200X Offline Data Repair |
| RTS file extension | RealNetworks | RealAudio RTSL Document |
| RTSL file extension | N/A | RealAudio RTSL Document |
| RTSP file extension | Apple, Inc. | Apple QuickTime Real-time Streaming Protocol |
| RTSTN file extension | RapidSolution Software | Audials Station Format |
| RTSX file extension | code4ward | Royal TS Document Settings |
| RTT file extension | RagTime GmbH | Ragtime |
| RTTTL file extension | Nokia Corporation | RTTTL / Nokring Mobile Ring-tone Format |
| RTU file extension | Guru3D.com | RivaTuner Update |
| RTW file extension | MathWorks, Inc. | Real-Time Workshop Database |
| RTWSH file extension | RapidSolution Software | Radiotracker Wishlist Format |
| RT_ file extension | Microsoft Corporation | Microsoft Windows Winhelp Compressed |
| RU file extension | N/A | JavaSoft JRE 1.3 Library |
| RUB file extension | The jQuery Foundation | JQuery Rules |
| RUF file extension | Samsung | Samsung DVD And Blu-ray Player Firmware Format |
| RUJ file extension | Oracle Corporation | Oracle Recovery-Unit Journal |
| RUL file extension | N/A | Rule Format |
| RULE file extension | Microsoft Corporation | Visual C++ Project Rules |
| RULESET file extension | Microsoft | Microsoft Visual Studio Code Analysis Ruleset Format |
| RUM file extension | RAD Game Tools | Bink Video Subtitle Format |
| RUN file extension | N/A | Linux Executable Format |
| RUP file extension | IBM | IBM Rational Unified Process |
| RUS file extension | GPS Moldova | Navitel Navigator Map |
| RV file extension | RealNetworks | RealVideo Video Format |
| RV3 file extension | DJI Interprises, LLC | Newsbin Pro |
| RV9 file extension | RealNetworks, Inc. | RealVideo Movie |
| RVB file extension | Robert McNeel & Associates | Rhinoceros 3D Visual Basic Script |
| RVC file extension | MicroImages, Inc. | TNTmips Windows Version Project |
| RVD file extension | softelec | VPHybridCAD Native Drawing Format |
| RVDATA file extension | Enterbrain | RPG Maker Data Format |
| RVDATA2 file extension | Enterbrain, Inc. | RPG Maker VX Data |
| RVF file extension | Sergey Tkachenko | RichView Document |
| RVG file extension | Autodesk, Inc. | Revit External Group |
| RVI file extension | Eidos Interactive Ltd. | Revenant Game Archive |
| RVID file extension | Ambrosia Software | Snapz Pro X Video Format |
| RVL file extension | muvee | Muvee Project |
| RVM file extension | Eidos Interactive Ltd. | Revenant Game Archive |
| RVMAT file extension | Bohemia Interactive | Armed Assault Texture |
| RVP file extension | Microsoft Corporation | Microsoft Scan Configuration |
| RVPROJ file extension | Enterbrain | RPG Maker VX Project Format |
| RVPROJ2 file extension | Enterbrain, Inc. | RPG Maker VX Project |
| RVR file extension | Eidos Interactive Ltd. | Revenant Game Archive |
| RVS file extension | RasterVect Software | RasterVect Raster And Vector Graphics |
| RVT file extension | Autodesk | Autodesk Revit Architecture Project Format |
| RVW file extension | Element River, LLC. | ReviewMate Review |
| RVX file extension | RealNetworks | Real Protected Video Format |
| RW file extension | mackoy | BVE Trainsim Railway Definition |
| RW2 file extension | Panasonic | Panasonic Lumix RAW Image Format |
| RW3 file extension | Realmac Software | RapidWeaver Site Design Format |
| RW5 file extension | Spectra Precision | Survey Pro Data |
| RWA file extension | ReliaSoft Corporation | Weibull++ |
| RWC file extension | Wind Energy Division at Risø DTU, Denmark | WAsP Regional Wind Climate |
| RWD file extension | NRG Systems | RWD Compressed Game Archive |
| RWG file extension | Gammadyne | Random Word Generator File Format |
| RWK file extension | Bentley Systems, Incorporated | Bentley InRoads Project |
| RWL file extension | Leica | D-Lux 4 RAW Image Format |
| RWLIBRARY file extension | Mariner Software | Paperless Receipt Library Format |
| RWM file extension | Microsoft Corporation | Windows Imaging Resource Only |
| RWO file extension | MathWorks, Inc. | Matlab Output |
| RWP file extension | Realmac Software | RapidWeaver Web Package Format |
| RWPLUGIN file extension | Realmac Softwaree | RapidWeaver Plugin Format |
| RWR file extension | Sonoma Wire Works | RiffWorks IntelliRiffer |
| RWS file extension | eEye Digital Security | Retina Wireless Scanner Format |
| RWSNIPPET file extension | Realmac Software | RapidWeaver Snippet Format |
| RWSTYLE file extension | Realmac Software | RapidWeaver Style Format |
| RWSW file extension | Realmac Software | RapidWeaver Website Saved Project |
| RWTHEME file extension | Realmac Software | RapidWeaver Theme Format |
| RWTL file extension | ResearchWare, Inc. | HyperRESEARCH |
| RWX file extension | AOL Inc. | Netscape Live 3D |
| RWZ file extension | Microsoft | Microsoft Outlook Internet Rules Settings Format |
| RX file extension | Microsoft Corporation | MS-DOS 7 |
| RX2 file extension | Propellerhead Software | ReCycle! Audio Loop Format |
| RX3 file extension | Electronic Arts, Inc. | FIFA 11 Texture |
| RXC file extension | Sonic Solutions | Roxio Certificate Format |
| RXD file extension | Attachmate Corporation | Attachmate Reflection X Manager Definition |
| RXDATA file extension | N/A | RPG Maker RMXP Data Format |
| RXE file extension | The LEGO Group | Lego Mindstorms NXT Executable Format |
| RXL file extension | Seetrax CAE Ltd. | Seetrax Ranger CAD Drawing |
| RXM file extension | Attachmate Corporation | Reflection X Multi Session |
| RXML file extension | Roxen Internet Software AB | Roxen Macro Language |
| RXP file extension | Roxio | Easy CD & DVD Creator 6 Playlist |
| RXPROJ file extension | Enterbrain, Inc. | RPG Maker Project |
| RXS file extension | Remedy Interactive, Inc. | RSIGuard RSIScript |
| RXX file extension | Eugene Roshal | RAR Compressed Files From A Multi-volume Archive |
| RZ file extension | N/A | Rzip Compressed Archive |
| RZB file extension | Red Zion | Red Zion E-book Book Format |
| RZK file extension | Red Zion | File Crypt Password Format |
| RZN file extension | Red Zion | Red Zion E-book Notes Format |
| RZR file extension | N/A | Renamed WinRAR Archive |
| RZS file extension | Red Zion | Red Zion Security Format |
| RZX file extension | Red Zion | File Crypt Encrypted Format |
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