| .R01 | Various Developers | Arquivos de dados | WinRAR Split Archive Part 1 | 7-Zip | Igor Pavlov |
| .R1W | Micro Focus International plc | Arquivos de dados | Reflection Settings | Reflection software | Micro Focus International plc |
| .R2W | Micro Focus International plc | Arquivos de dados | Reflection Settings | Reflection software | Micro Focus International plc |
| .R5 | Unknown Developer | Arquivos de dados | Unknown Apple II File. (found On Golden Orchard Apple II CD Rom) | Atom | GitHub, Inc. |
| .R8 | Unknown Developer | Arquivos de dados | RAW Graphics File | Unknown Software | Unknown Developer |
| .RA6 | ReliaSoft | Arquivos de dados | ReliaSoft ALTA 6 File | ReliaSoft ALTA | HBM PRENSCIA INC. |
| .RAB | Pearson | Arquivos de dados | Encyclopedia Britannica 2002 Deluxe Edition Data | Encyclopedia Britannica 2002 Deluxe Edition | Pearson |
| .RAC | Concept2 Inc. | Arquivos de dados | Venue Race Application File Format | Venue Race Application | Concept2 Inc. |
| .RAI | Astronomical Institute of the Czech Academyof Sciences | Arquivos de dados | SPEFO Data | SPEFO | Astronomical Institute of the Czech Academyof Sciences |
| .RAN | Owen F. Ransen | Arquivos de dados | Dexterpen File | Dexterpen | Owen F. Ransen |
| .RAR | Rocky Sand Studio | Arquivos de dados | WinRAR Compressed Archive | 7-Zip | Igor Pavlov |
| .RAT | World Wide Web Consortium (W3C) | Arquivos de dados | PICS Rating File | Microsoft Notepad | Microsoft Corporation |
| .RBD | Jdobbs Software | Arquivos de dados | DVD Rebuilder File | DVD Rebuilder | Jdobbs Software |
| .RBG | Just Great Software | Arquivos de dados | RegexBuddy GREP Action Data | Regexbuddy | Just Great Software |
| .RBI | Robert Bentley, Inc. | Arquivos de dados | eBahn Reader Data | eBahn Desktop | Robert Bentley, Inc. |
| .RBL | Just Great Software | Arquivos de dados | RegexBuddy Library File | Regexbuddy | Just Great Software |
| .RBO | Xojo, Inc | Arquivos de dados | REALbasic Class File | Xojo | Xojo, Inc |
| .RBT | The LEGO Group | Arquivos de dados | LEGO MINDSTORMS NXT Program | LEGO MINDSTORMS NXT | The LEGO Group |
| .RCB | RealityRipple Software | Arquivos de dados | Ripple Chat Bot Document File | Ripple Chat Bot | RealityRipple Software |
| .RCD | Symantec Corporation | Arquivos de dados | PcAnywhere Recorded Session File | pcAnywhere | Symantec Corporation |
| .RCF | Rhapsody International | Arquivos de dados | Audiogalaxy Rhapsody Storage File | Rhapsody | Rhapsody International |
| .RCG | Neil Fraser | Arquivos de dados | Recog Character Recognition Set | Recog | Neil Fraser |
| .RCH | Grassland, Soil and Water Research Laboratory | Arquivos de dados | SWAT Reach Output File | SWAT | Grassland, Soil and Water Research Laboratory |
| .RCK | Building Energy Codes | Arquivos de dados | REScheck Data File | REScheck | Building Energy Codes |
| .RCM | Faithlife | Arquivos de dados | Logos Library System Verse Map | Unknown Software | Unknown Developer |
| .RCX | The LEGO Group | Arquivos de dados | Lego Mindstorms Data | LEGO MINDSTORMS NXT | The LEGO Group |
| .RC_ | Microsoft Corporation | Arquivos de dados | Microsoft WinHelp Compressed Help Document | Microsoft Windows Help | Microsoft Corporation |
| .RD1 | DATAIR | Arquivos de dados | DATAIR Data File | DATAIR Pension Reporter | DATAIR |
| .RDA | Open Source | Arquivos de dados | R Data File | R | The R Foundation |
| .RDATA | The R Foundation | Arquivos de dados | R Workspace File | R | The R Foundation |
| .RDB | EMC | Arquivos de dados | Retrospect Backup Set | Retrospect | Retrospect Inc. |
| .RDC | IBM | Arquivos de dados | IBM Voice Type Languages Scripts Data File | Mozilla Firefox | Mozilla |
| .RDD | ReliaSoft | Arquivos de dados | ALTA File | ReliaSoft ALTA | HBM PRENSCIA INC. |
| .RDF | Unknown Developer | Arquivos de dados | Resource Description Framework File | Mozilla Firefox | Mozilla |
| .RDH | Siemens AG | Arquivos de dados | Siemens MR Spectroscopy Header Data | MR Spectroscopy | Siemens AG |
| .RDT | Adobe Systems Incorporated | Arquivos de dados | Adobe Captivate RoboDemo Template File | Adobe Captivate | Adobe Systems Incorporated |
| .RDV | Nikolai Teofilov | Arquivos de dados | NTgraph Data | NTgraph | Nikolai Teofilov |
| .RDX | Borland | Arquivos de dados | Reflex Data File | Borland Reflex | Borland |
| .READ | Apple | Arquivos de dados | Golden Orchard Apple II CD Rom File | Apple OS X | Apple |
| .REASON | Propellerhead | Arquivos de dados | REASON File | Reason | Propellerhead |
| .REB | REBOL Technologies | Arquivos de dados | REBOL Script File | REBOL/View | REBOL Technologies |
| .REC | TOPFIELD Co., Ltd. | Arquivos de dados | Topfield PVR Recording | Squared 5 MPEG Streamclip | Open Source |
| .REF | Clark Labs | Arquivos de dados | IDRISI Raster Image Reference File | GDAL | Open Source |
| .REFERENCE | Budget In Brief | Arquivos de dados | Budget In Brief Reference File | Microsoft Notepad | Microsoft Corporation |
| .REGISTER | Apple | Arquivos de dados | Golden Orchard Apple II CD Rom File | Apple OS X | Apple |
| .REL | Nintendo | Arquivos de dados | Relocatable Module File | Stage Switcher | Unknown Developer |
| .RELEASE | Apple | Arquivos de dados | Golden Orchard Apple II CD Rom File | Apple OS X | Apple |
| .REMOVE | Apple | Arquivos de dados | Golden Orchard Apple II CD Rom File | Apple OS X | Apple |
| .REO | Unknown Developer | Arquivos de dados | Unknown Apple II File. (found On Golden Orchard Apple II CD Rom) | Atom | GitHub, Inc. |
| .REP | Rockstar Games | Arquivos de dados | Grand Theft Auto Replay File | Grand Theft Auto III | Rockstar Games |
| .REPORT | Sublime HQ Pty Ltd | Arquivos de dados | Report File | Microsoft Notepad | Microsoft Corporation |
| .REPORTS | Apple | Arquivos de dados | Golden Orchard Apple II CD Rom File | Apple OS X | Apple |
| .REQU | Apple | Arquivos de dados | Golden Orchard Apple II CD Rom File | Apple OS X | Apple |
| .REQUEST | Apple | Arquivos de dados | Golden Orchard Apple II CD Rom File | Apple OS X | Apple |
| .RESCUE | Unknown Developer | Arquivos de dados | Unknown Apple II File. (found On Golden Orchard Apple II CD Rom) | Atom | GitHub, Inc. |
| .RESPECT | Apple | Arquivos de dados | Golden Orchard Apple II CD Rom File | Apple OS X | Apple |
| .RET | SAP | Arquivos de dados | BusinessObjects Template | SAP BusinessObjects Business Intelligence | SAP |
| .REUNION | Apple | Arquivos de dados | Golden Orchard Apple II CD Rom File | Apple OS X | Apple |
| .REVE | Apple | Arquivos de dados | Golden Orchard Apple II CD Rom File | Apple OS X | Apple |
| .REWARD | Apple | Arquivos de dados | Golden Orchard Apple II CD Rom File | Apple OS X | Apple |
| .REX | Propellerhead | Arquivos de dados | ReCycle Loop File | Avid Pro Tools | Avid Technology |
| .REZ | Monolith Productions | Arquivos de dados | Lithtech Game Engine Resource File | Dragon UnPACKer | Open Source |
| .REZCODE | Apple | Arquivos de dados | Golden Orchard Apple II CD Rom File | Apple OS X | Apple |
| .RF | Adobe Systems Incorporated | Arquivos de dados | Adobe FrameMaker Document | Adobe FrameMaker | Adobe Systems Incorporated |
| .RFA | Autodesk, Inc. | Arquivos de dados | Revit Family File | AutoCAD Architecture | Autodesk, Inc. |
| .RFI | Astronomical Institute of the Czech Academyof Sciences | Arquivos de dados | SPEFO Stellar Spectra Analysis Data | SPEFO | Astronomical Institute of the Czech Academyof Sciences |
| .RFL | Propellerhead | Arquivos de dados | Reason ReFill Sound Bank File | Reason | Propellerhead |
| .RFO | Siber Systems | Arquivos de dados | RoboForm Option File | RoboForm | Siber Systems |
| .RFR | Adobe Systems Incorporated | Arquivos de dados | Adobe Photoshop Frame Filter | Adobe Photoshop | Adobe Systems Incorporated |
| .RFU | Hewlett-Packard | Arquivos de dados | Remote Firmware Update | HP Remote Firmware Update | Hewlett-Packard |
| .RFX | Unknown Developer | Arquivos de dados | TouchStar License | Unknown Software | Unknown Developer |
| .RGA | Unknown Developer | Arquivos de dados | Residual Gas Analyzer Data File | Unknown Software | Unknown Developer |
| .RGE | Microsoft Corporation | Arquivos de dados | Entourage File Archive | Microsoft Outlook 2016 | Microsoft Corporation |
| .RGF | The LEGO Group | Arquivos de dados | LEGO MINDSTORMS EV3 Robot Graphics File | LEGO MINDSTORMS EV3 | The LEGO Group |
| .RGO | Cerience Corporation | Arquivos de dados | RepliGo File | RepliGo Viewer | Cerience Corporation |
| .RGT | Relic Entertainment | Arquivos de dados | Relic Entertainment Game Texture File | Corsix's Mod Studio | Open Source |
| .RHK | Symantec Corporation | Arquivos de dados | Backdoor.Win32.Rbot.rhk Data | AVG Antivirus | AVG Technologies |
| .RI | IBM | Arquivos de dados | IBM Lotus 1-2-3 File | Lotus 1-2-3 | IBM |
| .RIO | IBM | Arquivos de dados | IBM AIX System Data | IBM AIX | IBM |
| .RIP | IBM | Arquivos de dados | Lotus Notes Error File | IBM Lotus Notes | IBM |
| .RIR | APNIC | Arquivos de dados | RIR Statistics Exchange Format Data | RIR Explorer | APNIC |
| .RIV | Open Source | Arquivos de dados | CRiSP Harvest File | CRiSP Harvest | Open Source |
| .RL | R.LAB | Arquivos de dados | R.viewer List File | R.viewer | R.LAB |
| .RLELZW | Apple | Arquivos de dados | Golden Orchard Apple II CD Rom File | Apple OS X | Apple |
| .RLG | ReliaSoft | Arquivos de dados | ReliaSoft Weibull++ Data | ReliaSoft Weibull++ | ReliaSoft |
| .RLL | Microsoft Corporation | Arquivos de dados | Microsoft Resource Library | Microsoft Visual Studio | Microsoft Corporation |
| .RLO | Unknown Developer | Arquivos de dados | Basic Realizer Careal Library File | Unknown Software | Unknown Developer |
| .RLT | ReliaSoft | Arquivos de dados | ReliaSoft BlockSim & Weibull++ Data | ReliaSoft Weibull++ | ReliaSoft |
| .RLV | Tacx | Arquivos de dados | Tacx Fortius File | Fortius VR Trainer | Tacx |
| .RLZ | CA Technologies | Arquivos de dados | Basic CA-Realizer File | CA-Realizer | CA Technologies |
| .RM5 | Cochrane Community | Arquivos de dados | RevMan Review File | RevMan | Cochrane Community |
| .RMB | SCRIPTMATION | Arquivos de dados | RegistryMaster Data File | RegistryMaster | SCRIPTMATION |
| .RMC | WSDOT | Arquivos de dados | RMCalc Data | RMCalc | WSDOT |
| .RMD | Thomson Reuters Corporation | Arquivos de dados | Reference Manager Data File | Reference Manager | Thomson Reuters Corporation |
| .RMGB | RootsMagic, Inc. | Arquivos de dados | RootsMagic V4 Database Backup | RootsMagic | RootsMagic, Inc. |
| .RMGC | RootsMagic, Inc. | Arquivos de dados | RootsMagic V4 Genealogy Database | RootsMagic | RootsMagic, Inc. |
| .RMH | Microsoft Corporation | Arquivos de dados | Rights-Managed HTML Document File | Internet Explorer | Microsoft Corporation |
| .RMK | Grafx Software Development Tools | Arquivos de dados | CA Clipper RMake Makefile | CA-Clipper | CA Technologies |
| .RMX | RealNetworks | Arquivos de dados | RealJukebox Format | RealPlayer Cloud | RealNetworks |
| .RN | Nota Bene | Arquivos de dados | Nota Bene XPL Program | Nota Bene | Nota Bene |
de 2 
