| .USR | FileMaker Inc. | File di settaggi | FileMaker Pro Database File | FileMaker Pro | FileMaker Inc. |
| .UTI | BioWare | File di settaggi | Bioware Aurora Item Data | BioWare Neverwinter Nights | BioWare |
| .UTS | BioWare | File di settaggi | BioWare Aurora Game Engine Sound File | BioWare Neverwinter Nights | BioWare |
| .UVOPT | Keil | File di settaggi | µVision Project Options | µVision4 | Keil |
| .UVOPTX | Keil | File di settaggi | µVision Configuration | µVision4 | Keil |
| .VBOX | Oracle Corporation | File di settaggi | Oracle VM VirtualBox Settings File | Oracle VM VirtualBox | Oracle Corporation |
| .VCA | Interscape | File di settaggi | VAKCER Project Tracker Add-in | VAKCER Project Tracker | Interscape |
| .VCF | Palm | File di settaggi | VCard File | Microsoft Outlook Express | Microsoft Corporation |
| .VCL | Open Source | File di settaggi | Varnish Configuation File | Varnish Cache | Open Source |
| .VCPREF | Symantec Corporation | File di settaggi | Norton Antivirus Preferences File | Norton Security | Symantec Corporation |
| .VCW | Microsoft Corporation | File di settaggi | eMbedded Visual C++ Workspace File | Microsoft Visual Studio | Microsoft Corporation |
| .VFO | Silicon Graphics, Inc. | File di settaggi | Silicon Graphics Onyx2 Video Format Combiner File | Video Format Combiner | Silicon Graphics, Inc. |
| .VIM | Bram Moolenaar | File di settaggi | Vim Settings File | Vim | Bram Moolenaar |
| .VLT | zilliondigits | File di settaggi | WinVault File Archive | WinVault | zilliondigits |
| .VMC | Microsoft Corporation | File di settaggi | Windows Virtual Machine Configuration File | VMware Workstation | VMware |
| .VMT | VMware | File di settaggi | VMware Configuration File | VMware Workstation | VMware |
| .VMTM | VMware | File di settaggi | VMware Team Data File | VMware Workstation | VMware |
| .VMX | VMware | File di settaggi | VMware Configuration File | VMware Workstation | VMware |
| .VMXF | VMware | File di settaggi | VMware Team Member File | VMware Workstation | VMware |
| .VPH | optikVerve Labs | File di settaggi | VirtualPhotographer Custom Settings | Adobe Photoshop | Adobe Systems Incorporated |
| .VPL | Unknown Developer | File di settaggi | Karaoke Player Playlist | vanBasco's Karaoke Player | Open Source |
| .VPS | H+H Software GmbH | File di settaggi | Virtual CD Copy Template | H+H Software Virtual CD | H+H Software GmbH |
| .VQS | Datapath | File di settaggi | Datapath X4 Configuration File | Datapath X4 | Datapath |
| .VRE | ASG Technologies | File di settaggi | ASG Remote Desktop Settings | ASG-Remote Desktop | ASG Technologies |
| .VRP | Incendo Technology | File di settaggi | Vectir Profile Template File | Vectir | Incendo Technology |
| .VSC | McAfee, Inc. | File di settaggi | McAfee VirusScan Configuration File | McAfee VirusScan Enterprise | McAfee, Inc. |
| .VSIXLANGPACK | Microsoft Corporation | File di settaggi | Microsoft Visual Studio Localised VSIX Package | Microsoft Visual Studio | Microsoft Corporation |
| .VSPROPS | Microsoft Corporation | File di settaggi | Microsoft Visual Studio Project Property Sheet File | Microsoft Visual Studio | Microsoft Corporation |
| .VSPSCC | Microsoft Corporation | File di settaggi | Visual Studio Project Source Control Data | Microsoft Visual Studio | Microsoft Corporation |
| .VSSETTINGS | Microsoft Corporation | File di settaggi | Visual Studio Settings File | Microsoft Visual Studio | Microsoft Corporation |
| .VSW | Microsoft Corporation | File di settaggi | Visio Workspace File | Microsoft Visio 2016 | Microsoft Corporation |
| .VUE | E-on Software, Inc. | File di settaggi | Vue Scene File | E-on Vue | E-on Software, Inc. |
| .VUI | Jeppesen Marine, Inc. | File di settaggi | Visual Navigation Suite Exported Settings | Visual Navigation Suite | Jeppesen Marine, Inc. |
| .VWP | Raven software | File di settaggi | Vehicle Weapon File | Raven Software Star Wars Jedi Knight: Jedi Academy | Valve |
| .VXP | Interscape | File di settaggi | Mobile Application File | Mediatek MRE SDK | MediaTek |
| .W3D | Adobe Systems Incorporated | File di settaggi | Adobe Shockwave 3D File | Adobe Director | Adobe Systems Incorporated |
| .WAT | IBM | File di settaggi | IBM Voice Type Languages Map Data | IBM Voice Type | IBM |
| .WB4 | Stardock Corporation | File di settaggi | WindowBlinds Default Skin | WindowBlinds | Stardock Corporation |
| .WC | Valve | File di settaggi | Valve Hammer Configuration File | Valve Hammer Editor | Valve |
| .WCR | Open Source | File di settaggi | Ergane Configuration File | Ergane | Open Source |
| .WCX | Microsoft Corporation | File di settaggi | RemoteApp And Desktop Connections Configuration File | Remote Desktop Manager | Devolutions |
| .WCZ | SoftShape | File di settaggi | Chameleon Clock Wallpaper File | Chameleon Clock | SoftShape |
| .WFC | Microsoft Corporation | File di settaggi | Windows Wireless Network Settings File | MacroMates TextMate | MacroMates |
| .WFP | Turtle Beach Corporation | File di settaggi | WaveFront Program File | Turtle Beach WaveFront Software | Turtle Beach Corporation |
| .WFW | Microsoft Corporation | File di settaggi | Windows Firewall Policy File | Microsoft Windows Server 2016 | Microsoft Corporation |
| .WFX | Adobe Systems Incorporated | File di settaggi | Adobe User Keyboard Shortcut Settings | Adobe Creative Cloud | Adobe Systems Incorporated |
| .WIF | Canyon Art | File di settaggi | Weaving Interchange Format File | Art WeaveIt (Art iWeaveIt for iOS and Android) | Canyon Art |
| .WLM | Pierre-Emmanuel Gougelet | File di settaggi | CompW Image Format File | XnView MP | XnSoft |
| .WME | Microsoft Corporation | File di settaggi | Windows Media Encoder Session File | Microsoft Windows Media Encoder 9 | Microsoft Corporation |
| .WMS | Microsoft Corporation | File di settaggi | Windows Media Skin | Microsoft Windows Media Player | Microsoft Corporation |
| .WMZ | Microsoft Corporation | File di settaggi | Compressed Windows Media Player Skin | Microsoft Windows Media Player | Microsoft Corporation |
| .WPJ | Watcom International Corporation | File di settaggi | Watcom C/C++ Project | Watcom C/C++ | Open Source |
| .WPP | Serif | File di settaggi | WebPlus Project File | Serif WebPlus | Serif |
| .WPS | Kingsoft | File di settaggi | Kingsoft Writer Document | WPS Office | Kingsoft |
| .WPZ | Naviter | File di settaggi | SeeYou Waypoint File | SeeYou | Naviter |
| .WS | MicroPro International Corp. | File di settaggi | WordStar Document | Corel WordPerfect X8 | Corel |
| .WSA | Sonicle | File di settaggi | WebSynth Media File | WebSynth | Sonicle |
| .WSP | Microsoft Corporation | File di settaggi | SharePoint Solution Package | Microsoft Visual Studio | Microsoft Corporation |
| .WSS | Microsoft Corporation | File di settaggi | Microsoft Windows Sound System File | Microsoft Windows | Microsoft Corporation |
| .WSW | Aignes | File di settaggi | WebSite-Watcher Bookmark | WebSite-Watcher | Aignes |
| .WS_ | Unknown Developer | File di settaggi | Visc15 Adressen Setup File | Unknown Software | Unknown Developer |
| .WWK | Corel Corporation | File di settaggi | Corel WordPerfect Keyboard Layout File | Corel WordPerfect | Corel |
| .WWP | Microsoft Corporation | File di settaggi | Microsoft Works Wizards File | Microsoft Works | Microsoft Corporation |
| .WWS | Microsoft Corporation | File di settaggi | Microsoft Works Wizards File | Microsoft Works | Microsoft Corporation |
| .XC2 | Haliplex Communications | File di settaggi | DACCS Configuration File | HPXView | Haliplex Communications |
| .XCI | Adobe Systems Incorporated | File di settaggi | Adobe Reader Font Mapping File | Adobe Reader | Adobe Systems Incorporated |
| .XCU | Apache Software Foundation | File di settaggi | OpenOffice.org Configuration File | Apache OpenOffice | Apache Software Foundation |
| .XDC | Adobe Systems Incorporated | File di settaggi | Adobe Acrobat Printer Description | Adobe Acrobat DC | Adobe Systems Incorporated |
| .XDR | Microsoft Corporation | File di settaggi | XML-Data Reduced File | Microsoft Notepad | Microsoft Corporation |
| .XEE | Microsoft Corporation | File di settaggi | Microsoft Expression Encoder Preset | Expression Encoder | Microsoft Corporation |
| .XEM | X-Genics Limited | File di settaggi | eManager Metered Units | X-Genics eManager | X-Genics Limited |
| .XEP | X-Genics Limited | File di settaggi | eManager File Packaging Information | X-Genics eManager | X-Genics Limited |
| .XES | X-Genics Limited | File di settaggi | eManager Skins Definition | X-Genics eManager | X-Genics Limited |
| .XET | X-Genics Limited | File di settaggi | eManager Process Definition | X-Genics eManager | X-Genics Limited |
| .XEV | X-Genics Limited | File di settaggi | eManager Auto-Update File | X-Genics eManager | X-Genics Limited |
| .XGS | Microsoft Corporation | File di settaggi | XACT Global Settings File | Microsoft XACT | Microsoft Corporation |
| .XIP | Apple | File di settaggi | MacOS Signed Archive | Apple Archive Utility | Apple |
| .XJS | Newforms Technologies | File di settaggi | Jindent Settings File | Jindent | Newforms Technologies |
| .XLB | Microsoft Corporation | File di settaggi | Excel Toolbars File | Microsoft Excel | Microsoft Corporation |
| .XM2 | LexisNexis | File di settaggi | TextMap Version 2 Case Format File | TextMap | LexisNexis |
| .XMS | Alexander Gross | File di settaggi | Music Studio Project | Alexander Gross Music Studio | Alexander Gross |
| .XPF | Open Source | File di settaggi | Linux MultiMedia Studio Preset File | LMMS | Open Source |
| .XPL | Interscape | File di settaggi | LcdStudio Playlist File | LCDStudio | Interscape |
| .XPX | Intercon Associates | File di settaggi | Intercon FormNet File | Accessible FormNet | Intercon Associates |
| .XPY | Open Source | File di settaggi | XPY Settings File | XPY | Open Source |
| .XRX | Microsoft Corporation | File di settaggi | Expression Encoder Media Profile Settings | Expression Encoder | Microsoft Corporation |
| .XS | Microsoft Corporation | File di settaggi | Age Of Empires 3 Map AI Generator | Microsoft Age of Empires | Ensemble Studios |
| .XST | IBM | File di settaggi | WebSphere Query Template | WebSphere Application Server | IBM |
| .XTODVD | VSO Software | File di settaggi | ConvertXtoDVD Project File | ConvertXtoDVD | VSO Software |
| .XTP | adnx | File di settaggi | xTime Project Document | xPlan | adnx |
| .XUI | Microsoft Corporation | File di settaggi | Xbox 360 User Interface File | Microsoft Visual Studio | Microsoft Corporation |
| .XVM | VMware | File di settaggi | VMware Console Configuration File | VMware Workstation | VMware |
| .XWK | Intel Corporation | File di settaggi | Crosstalk Communicator Keyboard Mapping | Intel Crosstalk Communicator | Intel Corporation |
| .XXS | Sorenson Media | File di settaggi | Sorenson Squeeze Settings File | Squeeze | Sorenson Media |
| .YPF | David Binette | File di settaggi | YahElite Personality File | YahElite | David Binette |
| .ZAP | Check Point Software Technologies Ltd. | File di settaggi | ZoneAlarm Pro Data File | ZoneAlarm Antivirus | Check Point Software Technologies Ltd. |
| .ZHS | Zephyr | File di settaggi | ECLIPSE Server Hotspot File | Eclipse Server | Zephyr |
| .ZON | Nuance | File di settaggi | OmniPage Zone Template File | OmniPage | Nuance |
| .ZPF | AutoDesSys, Inc. | File di settaggi | Form•Z Preferences File | AutoDesSys formZ | AutoDesSys, Inc. |
| .ZVT | Adobe Systems Incorporated | File di settaggi | Photoshop Zoomify Preset File | Adobe Photoshop CC | Adobe Systems Incorporated |
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