.R | Open Source | Developer Files | R Script File | Microsoft Windows Media Player | Microsoft Corporation |
.R8 | Unknown Developer | Camera Raw Files | RAW Graphics File | Microsoft Flight Simulator | Microsoft Corporation |
.R82 | Microsoft Corporation | Graphic Files | Flight Simulator Texture File | Microsoft Flight Simulator | Microsoft Corporation |
.RAF | Fuji Xerox | Camera Raw Files | Fuji RAW Image File | ACD Systems Canvas | Microsoft Corporation |
.RAT | World Wide Web Consortium (W3C) | Uncommon Files | PICS Rating File | Microsoft Notepad | Microsoft Corporation |
.RATDVD | RatDVD | Disk Image Files | RatDVD Disk Image | Microsoft Windows Media Player | Microsoft Corporation |
.RAW | Unknown Developer | Camera Raw Files | Raw Image Data File | Microsoft Windows Photos | Microsoft Corporation |
.RB | Larian Studios | Game Files | Divinity: Original Sin Game Data | Visual Studio Code | Microsoft Corporation |
.RBF | Microsoft Corporation | Backup Files | Windows Installer Rollback File | Windows Installer | Microsoft Corporation |
.RBK | Microsoft Corporation | Backup Files | Windows 95 Registry Backup File | Microsoft Configuration Backup Tool | Microsoft Corporation |
.RBS | Microsoft Corporation | Backup Files | Windows Installer Rollback Script File | Windows Installer | Microsoft Corporation |
.RC | Angus Johnson | Developer Files | Resource Script File | Microsoft Visual Studio | Microsoft Corporation |
.RC2 | Microsoft Corporation | Developer Files | Visual Studio Resources File | Microsoft Visual Studio | Microsoft Corporation |
.RC3 | Microsoft Corporation | Developer Files | Vc98/Visual C Resource File | Microsoft Visual C++ | Microsoft Corporation |
.RCC | Angus Johnson | Developer Files | Resource Script File | Microsoft Visual Studio | Microsoft Corporation |
.RCJ | Microsoft Corporation | Text Files | Robocopy Job File | Microsoft Notepad | Microsoft Corporation |
.RCT | Microsoft Corporation | Settings Files | Visual Studio Resource Template | Microsoft Visual Studio | Microsoft Corporation |
.RC_ | Microsoft Corporation | Data Files | Microsoft WinHelp Compressed Help Document | Microsoft Windows Help | Microsoft Corporation |
.RDF | Unknown Developer | Settings Files | Resource Description Framework File | Microsoft Excel | Microsoft Corporation |
.RDG | Microsoft Corporation | Settings Files | Microsoft Remote Desktop Connection Manager Configuration | Microsoft Remote Desktop Connection | Microsoft Corporation |
.RDP | Microsoft Corporation | Settings Files | Remote Desktop Configuration File | Microsoft Remote Desktop Connection | Microsoft Corporation |
.REA | Microsoft Corporation | Text Files | Readme Text File | Microsoft Notepad | Microsoft Corporation |
.README | The Document Foundation | Text Files | Readme Text Document File | Microsoft Notepad | Microsoft Corporation |
.REFERENCE | Budget In Brief | Data Files | Budget In Brief Reference File | Microsoft Notepad | Microsoft Corporation |
.REG | Microsoft Corporation | System Files | Registry File | Windows Registry Editor | Microsoft Corporation |
.RELS | Microsoft Corporation | Page Layout Files | Open Office XML Relationships File | Microsoft Excel | Microsoft Corporation |
.REPORT | Sublime HQ Pty Ltd | Data Files | Report File | Microsoft Notepad | Microsoft Corporation |
.REQ | Open Source | Uncommon Files | SSL Certificate Request File | Microsoft Exchange Server | Microsoft Corporation |
.RES | Valve | Settings Files | Valve Resource File | Microsoft Visual Studio | Microsoft Corporation |
.RESJSON | Microsoft Corporation | Developer Files | Microsoft Windows 8 Metro JavaScript File | Microsoft Windows 8 | Microsoft Corporation |
.RESMONCFG | Microsoft Corporation | Settings Files | Microsoft Windows Resource Monitor Settings | Microsoft Resource Monitor | Microsoft Corporation |
.RESOURCES | Microsoft Corporation | Developer Files | Microsoft Visual Studio Resource | Microsoft Visual Studio | Microsoft Corporation |
.RESTORELIST | Microsoft Corporation | System Files | Microsoft Windows File System Permission | Microsoft Windows | Microsoft Corporation |
.RESW | Microsoft Corporation | Developer Files | Microsoft Windows 8 Resources File | Microsoft Windows 8 | Microsoft Corporation |
.RESX | Microsoft Corporation | Developer Files | .NET Managed Resources File | Microsoft Visual Studio | Microsoft Corporation |
.RGB | Silicon Graphics, Inc. | Raster Image Files | RGB Bitmap | ACD Systems Canvas | Microsoft Corporation |
.RGE | Microsoft Corporation | Data Files | Entourage File Archive | Microsoft Outlook 2016 | Microsoft Corporation |
.RGS | Microsoft Corporation | Executable Files | Registry Script | Microsoft Visual Studio | Microsoft Corporation |
.RH | Microsoft Corporation | Developer Files | C++ Resource Header Data | Microsoft Visual C++ | Microsoft Corporation |
.RHTML | Yukihiro “Matz” Matsumoto | Web Files | Ruby HTML Web Page | Internet Explorer | Microsoft Corporation |
.RJS | Yukihiro “Matz” Matsumoto | Web Files | Ruby Javascript File | Microsoft Edge | Microsoft Corporation |
.RL4 | Various Developers | Raster Image Files | Bitmap Image File | Microsoft Windows Photos | Microsoft Corporation |
.RLL | Microsoft Corporation | Settings Files | Microsoft Resource Library | Microsoft Visual Studio | Microsoft Corporation |
.RMH | Microsoft Corporation | Data Files | Rights-Managed HTML Document File | Internet Explorer | Microsoft Corporation |
.RMI | Open Source | Audio Files | RMID MIDI File | Microsoft Windows Media Player | Microsoft Corporation |
.RMT | The Catalina Group | System Files | Router Firmware File | Internet Explorer | Microsoft Corporation |
.RPC | Synthrone | Page Layout Files | Rich Page Content Document | Microsoft Visual Studio | Microsoft Corporation |
.RPT | SAP | Data Files | Crystal Reports File | Microsoft Visual Studio | Microsoft Corporation |
.RPY | Team Shanghai Alice | Game Files | Touhou Project Replay File | Microsoft Notepad | Microsoft Corporation |
.RRA | Iterum, LLC | CAD Files | vRigger Rigging Gear File | Windows Installer | Microsoft Corporation |
.RRT | ALTAVENTE | Data Files | Rhapzode Resource Template | Microsoft PowerPoint | Microsoft Corporation |
.RSP | Rockwell Automation Inc. | Data Files | RSLogix PLC Program File | Microsoft Visual Studio | Microsoft Corporation |
.RST | David Goodger | Text Files | ReStructuredText File | Microsoft Notepad | Microsoft Corporation |
.RTC | Brain Innovation | Data Files | BrainVoyager QX Design Matrix File | Internet Explorer | Microsoft Corporation |
.RTE | Autodesk, Inc. | Data Files | Revit Project Template | Microsoft Exchange Server | Microsoft Corporation |
.RTF | Microsoft Corporation | Text Files | Rich Text Format File | Microsoft WordPad | Microsoft Corporation |
.RTL | Hewlett-Packard | Raster Image Files | Raster Transfer Language File | Microsoft Notepad | Microsoft Corporation |
.RTP | KTH Royal Institute of Technology | Data Files | Gromacs Residue Topology Parameter File | MS-DOS | Microsoft Corporation |
.RTX | The Document Foundation | Text Files | Rich Text Document | Microsoft Word | Microsoft Corporation |
.RT_ | Microsoft Corporation | Data Files | Microsoft WinHelp Compressed Help Document | Microsoft Windows Help | Microsoft Corporation |
.RU | Microsoft Corporation | Text Files | Russian Text Or Localization File | Microsoft Notepad | Microsoft Corporation |
.RUF | Samsung Electronics | System Files | Samsung DVD And Blu-ray Player Firmware File | Windows Built-in USB Drive Software | Microsoft Corporation |
.RULESET | Microsoft Corporation | Settings Files | Visual Studio Code Analysis Rule Set | Microsoft Visual Studio | Microsoft Corporation |
.RV | Astronomical Institute of the Czech Academyof Sciences | Data Files | SPEFO Stellar Spectra Analysis Data | Microsoft Windows Media Player | Microsoft Corporation |
.RWD | NRG Systems | Data Files | NRG Raw Wind Data File | Microsoft Flight Simulator | Microsoft Corporation |
.RWZ | Microsoft Corporation | Uncommon Files | Outlook Rules Wizard File | Microsoft Outlook 2016 | Microsoft Corporation |
.RX | Microsoft Corporation | System Files | MS-DOS 7 Data | Microsoft Windows | Microsoft Corporation |