| .m | Objective-C Language Source Format |
| .m!95 | Adobe Director For Mac |
| .m-jpeg | M-JPEG |
| .m01 | MicroStation Modification Resource |
| .m10 | Microsoft Money 2002 Data |
| .m11 | Microsoft Money 2003 Data |
| .m12 | Microsoft Money 2004 Data Format |
| .m13 | Microsoft Media Viewer |
| .m14 | Microsoft Media Viewer |
| .m15 | Apple QuickTime Format |
| .m16 | Microsoft Money 2007 Data |
| .m1a | MPEG-1 Audiostream Format |
| .m1c | IBM Voice Type Languages Newuser |
| .m1i | IBM Voice Type Languages Newuser |
| .m1pg | IFinish Video Format |
| .m1s | MPEG-1 System Stream |
| .m1v | Moving Pictures Experts Group Video (MPEG-1 IPB) |
| .m2 | World Of Warcraft Model Object File Format |
| .m21 | MPEG-21 Video Format |
| .m25 | Symantec Endpoint Protection Manager |
| .m2a | MPEG-2 Audio |
| .m2c | IBM Voice Type Languages Newuser |
| .m2d | HTC Manila 2D For Windows Mobile Skin |
| .m2dct | HTC Manila 2D For Windows Mobile Skin |
| .m2f | Maxthon Filter Package |
| .m2i | IBM Voice Type Languages Newuser |
| .m2l | Maxthon Language Package |
| .m2m | TiMidity++ M2M Settings |
| .m2p | MPEG-2 Stream File Format |
| .m2r | Avaya Mib2Rules Perl Script |
| .m2s | MPEG-2 Audio Video Format |
| .m2t | MPEG-2 Transport Stream Format |
| .m2ts | MPEG-2 Stream (Blu-Ray) |
| .m2u | Maxthon Layout |
| .m2v | MPEG-2 Packetized Elementary Stream |
| .m3 | Blizzard StarCraft 2 MDX3 Model Format |
| .m32 | Duke Nukem 3D Script |
| .m3c | IBM Voice Type Languages Newuser |
| .m3d | DIALux 3D Object Format |
| .m3g | Nokia Mobile 3D Graphics Program Format |
| .m3h | Starcraft 2 Model Data |
| .m3i | IBM Voice Type Languages Newuser |
| .m3s | Myst III Exile Saved Game |
| .m3t | Myst 3 Exile Text |
| .m3u | MP3 Songs Playlist Format |
| .m3u8 | UTF-8 M3U Playlist Format |
| .m3url | SMIL MP3 Playlist |
| .m3v | DJ Mix Pro Playlist |
| .m3x | MAGIX Digital Photo Maker PhotoCD Playlist |
| .m4 | M4 Preprocessor Macro Format |
| .m4a | MPEG-4 Compressed Audio Format |
| .m4b | MPEG-4 Audio Layer Audio Book Format |
| .m4c | IBM Voice Type Language Newuser |
| .m4d | Sage MAS 90 Data |
| .m4e | MPEG-4 Video Format |
| .m4f | Sony Network Camera MPEG-4 Video |
| .m4i | IBM Voice Type Languages Newuser |
| .m4l | Sage MAS 90 Data |
| .m4p | Apple ITunes Music Store Audio Format |
| .m4r | Apple IPhone Ringtone Format |
| .m4s | Myst IV: Revelation Save Game |
| .m4t | Sage MAS 90 Table |
| .m4u | MPEG-4 Playlist Format |
| .m4v | MPEG-4 Video File Format |
| .m51 | ARM Keil Tools Linker Listing |
| .m64 | Mupen64 Movie Capture |
| .m68 | Turbo Pascal Dos |
| .m75 | Apple QuickTime Format |
| .m7a | MapKing Map |
| .m7d | MapKing Navigation Map |
| .m7p | Multilizer PDF Translator Project |
| .m8 | Heretic II MipMap Image |
| .m?? | Ingres Modify Table/Index |
| .ma | Autodesk Maya ASCII Scene Format |
| .ma0 | Diablo II Act 1 Saved Map Progress |
| .ma1 | Monarch Audio Format |
| .ma1.mmf | SMAF Synthetic Music Mobile Application Format |
| .ma2 | Bibexcel |
| .ma2.mmf | SMAF Synthetic Music Mobile Application Format |
| .ma3 | Harvard Graphics Macro |
| .mab | Mozilla Address Book Format |
| .mac | MacPaint Bitmap Image |
| .maca | MacWrite Document |
| .macbin | MacBinary Archive |
| .macp | Apple Macintosh MacPaint Bitmap Image |
| .macs | MADRIX Encrypted Script |
| .mad | Microsoft Access Module Shortcut Format |
| .mae | Maestro Molecular Model Format |
| .maf | Microsoft Access Form Shortcut Format |
| .maff | Mozilla Archive Format |
| .mag | Microsoft Access Diagram Shortcut Format |
| .magic | Magic Mail Monitor Configuration |
| .magik | Magik Source Code Format |
| .mahjongtitanssave-ms | Mahjong Titans Save Game Format |
| .mai | Microsoft Mail Message Format |
| .maildb | MSN Mail |
| .mailhost | E-mail Server Preferences Format |
| .mailloc | Apple Mac OS X Finder Mail Internet Location |
| .mailplanelicense | Mailplane License Format |
| .mailstationery | Apple Mail |
| .mailtoloc | Apple Mail Mail Address Format |
| .main | FileMaker Dictionary |
| .maj | Camduct Job |
| .mak | Make Format |
| .make | Makefile |
| .makefile | Make Format |
| .maker | Adobe Framemaker |
| .maki | Winamp MAKI Compiled Script |
| .mako | Mako Tamplate Format |
| .mal | MadAppLauncher Settings Format |
| .mam | Microsoft Access Macro Shortcut Format |
| .maml | Microsoft Assistance Markup Language |
| .man | Unix Text Manual Format |
| .managed_manifest | Silverlight Manifest |
| .mani | Mine-imator Project Format |
| .manifest | Manifest Format |
| .manifest-desktop | Ubuntu Desktop CD Manifest |
| .manm | Vietcong Game Data Format |
| .mao | Dragon Age Origins MAO XML |
| .map | Geographical Map Format |
| .mapimail | Windows Send To Mail Recipient Format |
| .maplet | Maplet World Format |
| .maplib | Mscape Map |
| .mapsdata | Apple IOS Map Data Format |
| .mapx | Mapjects GRYD Webserver Format |
| .maq | Microsoft Access Query Shortcut Format |
| .mar | Microsoft Access Report Shortcut Format |
| .marc | MAchine-Readable Cataloging (MARC) Document |
| .markdn | Markdown Markup Language Document Format |
| .markdown | Markdown Markup Language Format |
| .mars | Adobe Mars Format |
| .marshal | Marshal Editor Data Migration Model Format |
| .mart | Martview Ebook Format |
| .mas | Microsoft Access Stored Procedures Format |
| .mash | Java |
| .mask | SpeedGrade Color Mask Format |
| .masseffectprofile | Mass Effect User Profile |
| .masseffectsave | Mass Effect Saved Game |
| .master | ASP Master Page Format |
| .mat | Microsoft Access Table Shortcut Format |
| .match-rdb | RDB |
| .material | Rigs Of Rods Texture Reference Format |
| .math | AnalyticMath |
| .matlab | Matlab Script |
| .mato | Atomic Combat Saved Game Format |
| .matproj | Dragon Age Origins Material |
| .mau | Media Attachment Unit Format |
| .maud | Amiga MAUD Sound |
| .mav | Microsoft Access View Format |
| .maw | Microsoft Access Data Access Page Format |
| .max | 3D Studio Max Scene Format |
| .maxc | 3D Studio Max Container Format |
| .maxd | PaperPort Annotation |
| .maxm | Paperport |
| .maz | Microsoft Windows Hover! Maze Format |
| .mb | Autodesk Maya Binary Scene Format |
| .mb1 | Monster Bash Game Data |
| .mb3 | Minimal Board Editor (MBE) |
| .mb4 | Model Builder Model Design |
| .mba | Martus Human Rights Bulletin System |
| .mbac | MascotCapsule Resource |
| .mbas | MikroBasic Source Code |
| .mbb | ManaBook Format |
| .mbbk | ManaBook Book Kit Format |
| .mbc | Mulberry E-mail Client Cache |
| .mbd | Multimedia Builder MP3 Authoring Format |
| .mbdb | Apple IOS Backup Manifest |
| .mbdx | Apple IOS Backup Manifest |
| .mbe | MVP Baseball 2005 Game |
| .mbf | Microsoft Money Backup Format |
| .mbfavs | Stardent AVS X Bitmap Image |
| .mbfs | Stardent AVS X Bitmap Image |
| .mbfx | AVS X Image |
| .mbg | Mailbag Assistant E-mail Archive Format |
| .mbi | MagicISO Multi-bootable Information Format |
| .mbk | DBASE IV Multiple Index File Backup |
| .mbkp | Memeo Instant Backup Backup |
| .mbl | Logger Pro Experiment Data Format |
| .mbm | EPOC Multi-bitmap Format |
| .mbox | Mail Mailbox Format |
| .mbp | Mobipocket EBook Auxiliary Format |
| .mbp1 | Kindle Touch Annotation |
| .mbr | Zune Smooth Streaming Format |
| .mbs | Opera Mailbox Format |
| .mbsa | Microsoft Baseline Security Analyzer Format |
| .mbsb | Mamut Business Software Company Database Backup |
| .mbsyncstate | Mbsync Folder Backup |
| .mbt | Blue Card Manager Merit Badge Template Format |
| .mbtemmplate | ModelBaker Custom Template Directory |
| .mbv | JVC Everio MediaBrowser Movie |
| .mbw | Easy Mail Backup Wizard Format |
| .mbx | E-mail Mailbox Format |
| .mbz | Pogoshell NES Emulator Plugin |
| .mc | Microsoft Windows Localized Message Table Resource |
| .mc1 | MedCalc Data Format |
| .mc2 | MasterCook Cookbook Recipe Text Data Format |
| .mc3 | Bridge Design Modeler 3D Match-casting Geometry Control |
| .mc4d | Cinema 4D 3D Graphic |
| .mc5 | Poser 5 Material Format |
| .mc6 | Poser 6 Material Format |
| .mc8 | Mastercam V8 |
| .mc9 | Mastercam V9 CAD Format |
| .mca | Minecraft Anvil Format |
| .mcacc | MCACC Measurement Data |
| .mcb | NEPLAN Project |
| .mcbn | Microsoft Excel 4 For Mac Chart |
| .mcc | Amiga MUI External Class Library |
| .mcd | VectorWorks Drawing Format |
| .mcdb | Adobe Premiere Pro Media Cache Database |
| .mcdx | Mathcad Prime Document Format |
| .mcf | Mathcad Font Format |
| .mcfi | Autodesk Maya Initial Fluid Cache Format |
| .mcfp | Autodesk Maya Fluid Cache Playback Format |
| .mcgame | Minecraft Backup Format |
| .mci | Media Control Interface Command Script Format |
| .mck | Macro Keys Encrypted Macro |
| .mcl | Microsoft Media Center Application Shortcut Format |
| .mclevel | Minecraft Map Format |
| .mcmac | MacGourmet MasterCook Document |
| .mcmeta | Minecraft Animation Settings Format |
| .mcml | Microsoft Windows Media Center MCML |
| .mco | MSN Messenger Wink Format |
| .mcp | MSN Content Plus Installer Format Archive |
| .mcr | Autodesk 3D Studio Max Macroscript Format |
| .mcrp | MobyExplorer Encrypted Format |
| .mcs | MathCAD Raster Picture Image Format |
| .mcsp | My Craft Studio Project Format |
| .mcsx | My Craft Studio Professional Format |
| .mct | Musicator MIDI |
| .mcusw | Nokia Mobile Phones With Symbian Firmware |
| .mcv | ManyCam Effect |
| .mcw | Microsoft Word 5 For Mac Document Format |
| .mcworld | Minecraft World Backup Format |
| .mcx | Mastercam X And X2 File Format |
| .mcxe | MedicinesComplete Data Format |
| .mcxml | Microsoft Office 2013 XML Settings |
| .mcz | Poser Compressed Material Format |
| .md | MDCD Compressed File Archive |
| .md0 | Adobe Photoshop Format Browser Metadata Cache Format |
| .md03 | Adobe Director |
| .md1 | GEAR CD Suite CD Image Format |
| .md2 | Quake 2 Model Format |
| .md2p | MessengerDiscovery |
| .md2s | MessengerDiscovery |
| .md3 | Quake 3 Model Format |
| .md4 | Quake 3 MD4 Skeletal Model Format |
| .md5 | Checksum Format |
| .md5.txt | Message Digest 5 Hash Format |
| .md5anim | Doom 3 ID Tech 4 Game Engine Model Animation Format |
| .md5camera | Doom 3 ID Tech 4 Game Engine Model Camera Format |
| .md5mesh | Doom 3 ID Tech 4 Game Engine 3D Mesh Format |
| .md8 | GarageCUBE Modul8 Project Format |
| .mda | Microsoft Access Add-in Format |
| .mdat | REW Measurement |
| .mdb | Microsoft Access Database Format |
| .mdbackup | Apple IPhone Backup Format |
| .mdbhtml | Microsoft Office Access HTML Document Format |
| .mdbx | Access Based Database |
| .mdc | Image Minolta RD175 |
| .mdd | Point Oven Deformation Data Format |
| .mddata | Apple IPhone Backup Data Format |
| .mde | Microsoft Access Compiled Database (application) Format |
| .mdes | Trimaran Machine Description |
| .mdf | Alcohol 120% Disc Image File Format |
| .mdg | Enterprise Architect |
| .mdhtml | Microsoft Access HTML |
| .mdi | Microsoft Office Document Imaging File Format |
| .mdimporter | Spotlight Importer Setting |
| .mdinfo | Apple IPhone Info Format |
| .mdk | Astra Schedule Schedule |
| .mdl | Flight Simulator 95/98 3D Model Format |
| .mdle | Motion Description Language Extended |
| .mdm | HLM Multivariate Data Matrix Format |
| .mdmp | Microsoft Windows Minidump Format |
| .mdn | Microsoft Access Blank Database Template Format |
| .mdo | Alcohol 120% Split Image |
| .mdown | Markdown Markup Language Format |
| .mdp | Microsoft Visual C++ Visual J++ MAK File (old Project Workspace) |
| .mdpf | Mac OS X Modem Preferences |
| .mdpl | MacDraw II |
| .mdr | ZX Spectrum Microdrive Emulator |
| .mdrc | MADRIX DMX Remote Configuration |
| .mdrw | MacDraw |
| .mds | Alcohol 120% Image File (media Descriptor File) Format |
| .mdt | Microsoft Access Database Template Format |
| .mdtext | Markdown Markup Language |
| .mdtxt | Markdown Markup Language |
| .mdus | MessengerDiscovery |
| .mdv | QLAY |
| .mdw | Microsoft Access Workgroup Information Format |
| .mdwn | Markdown Markup Language |
| .mdx | Media Data EXtended Image Format |
| .mdz | Microsoft Access Wizard Template Format |
| .mdzip | MagicDraw Compressed Project Format |
| .me | Readme Text Format |
| .me2headmorph | Mass Effect 2 Head Morph |
| .me2mod | Mass Effect 2 Game Modification Format |
| .mea | Mastersizer 2000 Sample Analysis |
| .meb | PRO100 Library Format |
| .mech | Pro/MECHANICA Settings |
| .MeContact | Microsoft Live Messenger |
| .med | Amiga MED Sound Format |
| .mediawiki | Mediawiki Source |
| .mef | Mamiya ZD MEF Image Format |
| .meg | MEGA Data Format |
| .mega | Megacubo Metafile |
| .mel | Maya Embedded Language |
| .mell | RedleX Mellel Document Format |
| .mellel | RedleX Mellel Document Format |
| .mem | Microsoft Visual FoxPro Mem Format |
| .memb | Pro/ENGINEER Temporary |
| .men | MenuPro Restaurant Menu Design |
| .menc | Microsoft Windows Mobile Encrypted Format |
| .menu | Apple Mac OS X SystemUIServer MenuExtra Plugin Format |
| .menudata | VMWare Cache |
| .meo | MEO Encrypted Format |
| .meq | Corel WordPerfect Macro Editor Print Queue |
| .mer | Corel WordPerfect Macro Editor Resident Area Format |
| .merlin2 | Merlin Project Format |
| .merlinlicense | Merlin License Format |
| .mes | Corel WordPerfect Macro Editor Work Space |
| .mesa | OpenGL GLUT |
| .mesh | 3D Graphic Format |
| .met | EMule Cached Information Format |
| .meta | RealPlayer Metafile |
| .meta4 | Metalink 4.0 |
| .metadata_never_index | Spotlight Never Index Format |
| .metalink | Metalink 3.0 |
| .metastock | Metastock Data |
| .metriclog | Apple IOS Diagnostic |
| .meu | DOS Shell Menu Group |
| .mew | MultiEdit Configuration |
| .mex | Corel WordPerfect Macro Editor Expound Format |
| .mex4 | Sun-4/SPARC Dynamically Linked Subroutines |
| .mexds | MATlab Dynamically Linked Subroutines |
| .mexhp3 | Matlab HP9000/series 300 Dynamically Linked Subroutines |
| .mexhp7 | Matlab HP9000/series 700 Dynamically Linked Subroutines |
| .mexn | Matlab NeXT Dynamically Linked Subroutines |
| .mexrs6 | Matlab IBM RS/6000 Dynamically Linked Subroutines |
| .mexsg | Matlab Dynamically Linked Subroutine |
| .mexw32 | MATlab Program Executable |
| .mf | Java Manifest Format |
| .mf2 | Authorware Mediator5 Multimedia |
| .mf4 | Version 4.0 Measurement Data Format |
| .mfa | Multimedia Fusion Development Format |
| .MFAlist | Ashampoo Photo Commander Slideshow List |
| .mfasl | Netscape XUL Fastload Format |
| .mfcribbon-ms | MFC Ribbon Definition XML Format |
| .mfd | Adobe Multiple Master Font Metrics Directory |
| .mfe | Character Studio Format |
| .mff | Cakewalk MIDI |
| .mfg | ProEngineer Manufacturing |
| .mfi | Windows 98 Resource Kit |
| .mfil | Blizzard Software Update Format |
| .mfj | MOBCAL Data |
| .mfk | Memsoft OS/2 Database |
| .mfl | Mozilla Firefox XUL Fastload Format |
| .mfm | VTeX Multiple Master Font Metrics |
| .mfo | Mediaface Online CD Label Software Project Format |
| .mfp | MediaFACE CD Label Software Format |
| .mfps | Scientific Calculator Plus Script |
| .mfr | Autodesk Moldflow Result |
| .mfs | MetFS Encrypted FUSE Based Formatsystem Format |
| .mft | Mediaface Project Template Format |
| .mfu | Backdoor.Win32.Agent.mfu Virus Format |
| .mfv | MobileFrame Device Pack Format |
| .mfw | Motorola MSS Box Firmware Format |
| .mfx | Multimedia Fusion Extension Format |
| .mg | EarAche Audio |
| .mg1 | MusiGenesis Project |
| .mg2 | Band-in-a-Box Song |
| .mg4 | Band-in-a-Box Song |
| .mg9 | Band-in-a-Box Song |
| .mga | Manga Comics Document Format |
| .mgb | Paragon5 Gameboy Tracker Audio |
| .mgc | MGCSoft Equation Illustrator Data Format |
| .mgcb | MGCSoft Equation Illustrator Project Format |
| .mgd | Master Grade Gradebook |
| .mgdatabase | MacGourmet Deluxe Database Format |
| .mge | MGE Data Server Project |
| .mgf | ASCII-based 3D Rendering Materials And Geometry Format |
| .mgk | ImageMagick Settings Format |
| .mgl | Age Of Empires II Age Of Kings Game Format |
| .mglr | Magellan Routes |
| .mglt | Magellan Tracklogs |
| .mglw | Magellan Waypoint |
| .mgm | MGCSoft Equation Editor Macro File Format |
| .mgmf | MindGenius Mind Map |
| .mgmt | MindGenius 2-3 Template |
| .mgmx | MindGenius Map Format |
| .mgn | Modern Genealogy Database |
| .mgo | MacGourmet Recipe Format |
| .mgourmet | Mariner MacGourmet Document Format |
| .mgourmet3 | Mariner MacGourmet Document Format |
| .mgr | MGR Bitmap Image |
| .mgs | MGCSoft Vector Shapes Format |
| .mgspot | MacGourmet Metadata |
| .mgt | ZX Spectrum Emulator Disk Image |
| .mgtheme | MacGourmet Theme Format |
| .mgtx | MindGenius XML Template Format |
| .mgu | Band-in-a-Box MIDI |
| .mgv | Sony PSP Video Format |
| .mgx | Micrografx Designer Drawing Format |
| .mgz | Metal Gear Solid Game Archive |
| .mhd | Fallout 3 |
| .mhe | MHwinEHE Project |
| .mhk | Riven Movie Data |
| .mhp | Mailshift Internet Mail Document |
| .mhs | Xilinx Platform Studio Hardware Specification Format |
| .mht | Mime HTML (MHTML) Format |
| .mhtenx | Egis Encrypted HTM |
| .mhtm | Mime HTML (MHTML) |
| .mhtml | Mime MHTML Format |
| .mhtmlenx | Egis Encrypted MHTML |
| .mhv | Husqvarna Viking Data |
| .mi | AutoVue Graphic Plugin |
| .mi2 | Autodesk Softimage |
| .mi4 | NVidia PortalPlayer Firmware Update Format |
| .mib | MyInfo Topic Backup |
| .mic | Microsoft Image Composer Image Format |
| .mid | MIDI Audio Format |
| .midi | MIDI-sequention Sound Format |
| .mif | ImageMagick Image Format Format |
| .miff | Magick Image |
| .mig | Windows Easy Transfer Migration Data Format |
| .mih | MRtrix Image Header |
| .mii | Nintendo Wii Virtual Avatar Format |
| .mik | MapInfo MapImagery Encryption Key |
| .mil | Micro Illustrator Uncompressed Image |
| .milk | Winamp MilkDrop Plugin Configuration Format |
| .millpst | BobCAD Post Processor Data |
| .mim | Multi-Purpose Internet Mail Extensions Format |
| .mime | Multi-Purpose Internet Mail Extensions (MIME) File Format Format (RFC822) |
| .min | Minute Maker Format |
| .mindnode | MindNode Document Format |
| .mine | Minecraft Map Format |
| .minesweepersave-ms | Microsoft MineSweeper Save Format |
| .mingw32 | Mingw Compiler |
| .mini2sf | Nintendo DS Sound Information Format |
| .minincsf | NCSF Nintendo DS Audio Format |
| .minipsf | Miniature PlayStation Sound Format |
| .minipsf2 | Miniature PlayStation Sound Format |
| .miniso | DVDFab Miniso Disk Image |
| .miniusf | Nintendo 64 Song Format |
| .mint | Linux Mint Installer Format |
| .mio | MIO Multimedia Format |
| .mip | Corel PaintShop Pro Multiple Image Print Format |
| .mipr | MacImage Hybrid CD-ROM Project |
| .mir | Mini Image Ripper Disk Image Format |
| .miradi | Miradi Project |
| .mis | Mission Format |
| .miso | MacImage ISO+ Project |
| .mission | MissionMaker Project Format |
| .mit | MineEdit Inventory Template Format |
| .miv | MapImagery Vendor Profile |
| .mix | Microsoft PhotoDraw Image |
| .miz | Winamp Compressed Midi |
| .mj2 | JPEG 2000 Motion Sequence Format (ISO 15444-3) Format |
| .mj3 | Id Software Online Sale |
| .mjbooktemplate | MacJournal Book Template |
| .mjd | Adobe Acrobat MIME Encoded Job Definition Format |
| .mjdoc | MacJournal Document Format |
| .mjf | Mjuice MP3 Audio |
| .mjg | Trojan |
| .mjp | VTech MJP Video Format |
| .mjp2 | JPEG 2000 Motion Sequence Format (ISO 15444-3) |
| .mjpg | Motion JPEG Video Format |
| .mjr | Media Jukebox Registration |
| .mjz | Trojan.Win32.Agent.mjz |
| .mk | Make Format |
| .mk3d | Matroska MKV 3D Stereoscopic Video Format |
| .mk4 | Schiller Medilog ECG Raw Data Format |
| .mka | Matroska Audio Format |
| .mkb | Marmalade SDK Project |
| .mkc | MagicKey Currency Exchange Rate |
| .mkd | Markdown Markup Language |
| .mkdn | Markdown Markup Language |
| .mke | Microsoft Windows SDK Make |
| .mkext | Mac OS X Mach Kernel Extension Memory Cache |
| .mkey | CompeGPS Land Registration Key |
| .mkeyb | CompeGPS Land Registration Key |
| .mkh | WinMark Pro Mark |
| .mkII | Mark2 SoundSystem Audio |
| .mkj | MKJamz Audio |
| .mkp | Cinestar Remote Control Configuration |
| .mkr | Train Simulator Marker |
| .mks | Matroska Subtitles Stream |
| .mkt | Visual FoxPro Configuration |
| .mkv | Matroska Video-audio Multimedia Format |
| .mkv3D | Matroska 3D Video Format |
| .mky | MagicKey Configuration |
| .mkz | PokerOffice Database Backup |
| .ml | ML Language Source Code Format |
| .ml2 | Tripos MOL2 Molecule |
| .ml20 | Mercury Messenger For Mac Video |
| .ml3 | Milestones Project |
| .ml4 | Milestones 4 Schedule |
| .ml5 | Milestones Project |
| .ml9 | Milestones Professional 2004U Schedule |
| .mla | WorshipCenter Pro Document |
| .mlb | Microsoft Windows Mobile Media Library Format |
| .mlc | Microsoft Windows Language Interface Pack Format |
| .mld | I-Melody Format For I-Mode |
| .mle | MAirList Event List |
| .mlf | Package Download Profile |
| .mlg | IBM Communications Server Message |
| .mli | F# Source Code |
| .mlib | Model Library |
| .mlk | Sierra MasterCook Look Format |
| .mll | AutoDesk Maya Plug-in Format |
| .mlm | Novell GroupWise Saved Email Message |
| .mln | Alchemy Source |
| .mlocate | Gnome Desktop |
| .mlp | Meridian Lossless Packing Audio Format |
| .mlr | Mollier Sketcher |
| .mls | Miles Sound Tools Compressed DLS Format |
| .mlsxml | Skype XML |
| .mlt | Forecast Pro Multivariate Forecast |
| .mlv | LabVIEW Mathscript |
| .mlw | MainLog Data |
| .mlx | Starcraft Saved Game |
| .mly | OCaml Ocamlyacc Input |
| .mm | Apple Xcode Core Objective-C Program Source Code Format |
| .mm1 | ActiveXperts MMS Toolkit Settings |
| .mm3 | Mortgage Minder Saved Mortgage Configuration |
| .mm4 | Microsoft Windows Word Processing Format |
| .mm6 | Might And Magic 6 Saved Game Format |
| .mm7 | Might And Magic 7 Saved Game Format |
| .mm8 | MusicMaker V8 Audio Format |
| .mma | Master Album Maker Album Format |
| .mmap | MindManager Map Format |
| .mmas | MindManager Theme |
| .mmat | MindManager Template Format |
| .mmb | MultiMedia Builder |
| .mmc | Microsoft Office XP Media Content Format |
| .mmch | CodeWarrior Compiled Hdr |
| .mmcollection | Microsoft Outlook Mail Manager Plug-in Collection Format |
| .mmd | Mangodata Multi-user Database |
| .mmdc | MediaMonkey Mobile Device Settings Format |
| .mmdf | Multi-channel Memorandum Distribution Facility Mailbox Format |
| .mmdl | SAPPHIRE Structure Model |
| .mmdr | Adobe Director |
| .mme | Multipurpose Internet Mail Extensions Format |
| .mmf | Microsoft Mail Message Format |
| .mmg | MKVToolNix Muxing Settings |
| .mmh | Dragon Age Model Mesh Heirarchy |
| .mmip | MediaMonkey Installation Format |
| .mmjs | Adobe JavaScript Document |
| .mmk | MACSIMUS Define |
| .mml | Adobe FrameMaker Format |
| .mmm | MultiMedia Movie Format (RIFF RMMP) |
| .mmn | Memory-Map Navigator Overlay Object |
| .mmo | RapidFile Memo Document Format |
| .mmp | MixMeister Studio Playlist Format |
| .mmpa | MoreMotion Application Studio Page |
| .mmpf | CodeWarrior Preference |
| .mmpr | CodeWarrior Project |
| .mmpz | Linux MultiMedia Studio Project |
| .mmrc | MADRIX MIDI Remote Configuration |
| .mms | Miles Sound Tools |
| .mmsw | Movie Magic Screenwriter Document |
| .mmt | CoCo Systems VisiMap |
| .mmu | MyPM Merge Data Format |
| .mmv | MicroMV Movie Format |
| .mmw | AceMoney Financial Data Format |
| .mmx | Command And Conquer Game |
| .mmz | MusicMatch Theme |
| .mn1 | Microsoft Money Version 1 Data |
| .mn2 | Descent 2 Mission |
| .mn3 | Descent 3 Mission |
| .mn4 | Microsoft Money 95 Data |
| .mn5 | Microsoft Money 97 Data |
| .mn6 | Microsoft Money 98 Data |
| .mn7 | Microsoft Money 99 Data |
| .mn8 | Microsoft Money 2000 Data |
| .mn9 | Microsoft Money 2001 Data |
| .mnb | MuPAD |
| .mnc | AutoCAD Compiled Menu Format |
| .mnd | AutoCAD Menu Compiler |
| .mne | Microsoft Money |
| .mnf | ADAMS/Flex |
| .mng | Multiple Network Graphics |
| .mnh | Master Navigator Header Format |
| .mni | Star Trek Elite Force 2 Game |
| .mnit | FlashPeak SlimBrowser |
| .mnk | My Notes Keeper Notebook Format |
| .mnl | Autodesk AutoCAD Menu LISP Format |
| .mnm | Autodesk 3D Studio Max Character Studio Marker Name Format |
| .mno | Macromedia Design Note |
| .mnp | Ultrasoft Money |
| .mnr | Autodesk AutoCAD Compiled Menu Format |
| .mns | AutoCAD Interface Settings Format |
| .mnt | Visual FoxPro Additional Menu Description Format |
| .mnu | Autodesk AutoCAD Menu Format |
| .mnv | Sony PlayStation Movie Format |
| .mnx | Visual FoxPro Main (DBF) Menu Description Format |
| .mny | Microsoft Money Data Format |
| .mo | GNU Gettext Machine Object Format |
| .mo3 | MO3 MOD Audio Format |
| .mo? | Standard Mail Archive |
| .mob | MOBTV Video Format |
| .mobi | Mobipocket EBook Format |
| .mobileconfig | Apple IPhone Mobile Configuration Profile |
| .mobileprovision | IOS Mobile Device Provisioning Profile Format |
| .moc | MOCHA Java Script |
| .mocha | Adobe Mocha For Adobe After Effects |
| .mod | Hard Disk Camera Movie MPEG-2 Program Stream Format |
| .modd | Sony Video Analysis Format |
| .mode | Coda For Mac Plugin Format |
| .mode1v3 | Xcode Project Settings |
| .mode2v3 | Xcode Project Related |
| .model | CATIA V4 Model Format |
| .modelproj | Microsoft Visual Studio Modelling Project |
| .module | Drupal Module Format |
| .modus | Adobe Mocha For Adobe After Effects Modus |
| .mof | Systems Management Server Managed Object Format |
| .moff | Sony AVCHD Index Format |
| .mog | Football Mogul |
| .mogg | Multitrack Digital Audio Format |
| .moho | Anime Studio Animation Project Format |
| .moi | JVC Everio Digital Audio Format |
| .mojito | Limewire Kademlia |
| .mokey | Adobe Mocha For Adobe After Effects Mokey |
| .mol | MDL Molfile Molecule Format |
| .mol2 | Portable Representation Of A SYBYL Molecule |
| .mologiq | HTC EVO 3D |
| .mom | Managed Object Model |
| .momma | Offspring Fling Replay Format |
| .mon | Firefox Monday Bookmark Backup |
| .monet | Adobe Mocha For Adobe After Effects Monet |
| .money | Money Data Format |
| .moneywell | MoneyWell Financial Data Format |
| .monitorPanel | Apple Mac OS X Display Panel Extension |
| .mono | Bi-level Bitmap |
| .montage | Montage Screenplay Format |
| .monte | CRiSP Harvest |
| .moo | Apple QuickTime Movie Clip |
| .mood | Amarok Moodbar Data |
| .moov | Apple QuickTime Movie Format |
| .mop | MOPAC Input Format |
| .mopint | Mopac Internal Chemical Modeller Input |
| .mopout | MOPAC Chemical Output |
| .mopp | Havok Engine |
| .mor | Corel Shared Writing Tools |
| .morg | Morg |
| .morse | Ringtone Morse Code |
| .mos | Mamiya Digital Camera RAW Image Format |
| .mosaic | MacOSaiX Mosaic Format |
| .moss | Netscape Navigator For Mac HTML |
| .mot | LightWave Motion Format |
| .motn | Apple Motion Motion |
| .motor | Adobe Mocha For Adobe After Effects Motor |
| .mou | MOU Compressed Format |
| .mov | Apple QuickTime Digital Movie Format |
| .movie | Apple QuickTime Movie Format |
| .mox | ExtendSim Model Format |
| .moxel | Adobe Mocha For Adobe After Effects Moxel |
| .moz | Netscape Temporary Cache Format |
| .moz-backup | Mozilla Backup |
| .moz-delete | Mozilla Firefox Update |
| .moz-upgrade | Mozilla Firefox Upgrade |
| .mozeml | Mozilla Thunderbird Mail Message |
| .mp | Autodesk Maya Personal Learning Edition Format |
| .mp+ | MPEG Plus Audio |
| .mp1 | MPEG Audio Stream, Layer I Format |
| .mp10 | NI Multisim V10 Project Format |
| .mp11 | NI Multisim V11 Project Format |
| .mp2 | Sound File (MPEG-1 Layer II Audio Stream) |
| .mp21 | MPEG-21 Multimedia Format |
| .mp2a | Sound File (MPEG-1 Layer II Audio Stream) |
| .mp2m | Max Payne 2 Mod Format |
| .mp2s | Max Payne 2 Saved Game Format |
| .mp2v | MPEG Video Format |
| .mp3 | Compressed Audio And Music File, Mp3 Songs Or Ringtones |
| .mp3a | Renamed MP3 |
| .mp3g | WinCDG Pro MP3+G Karaoke |
| .mp4 | MPEG-4 Video File Format |
| .mp4.infovid | Parrot AR Drone And Gyro Flyer Video |
| .mp4a | MPEG-4 MP4A Codec Audio |
| .mp4b | MPEG-4 Audio Layer Bookmarkable |
| .mp4v | MPEG-4 Video Format |
| .mp5 | Maple Windows DOS |
| .mp7 | NI Multisim V7 Project Format |
| .mp8 | NI Multisim V8 Project |
| .mp9 | NI Multisim V9 Project Format |
| .mp? | LoseThos Compiler Map |
| .mpa | MPEG Audio Format |
| .mpb | MyPhoneExplorer Backup Format |
| .mpc | MusePack Audio Format |
| .mpcpl | Media Player Classics Playlist Format |
| .mpd | Microsoft Project Database Format |
| .mpdb | Windows Media Player Database |
| .mpdconf | Music Player Daemon Settings Format |
| .mpdp | MixPad Project Format |
| .mpds | MADRIX Plexus Settings |
| .mpe | MPEG Movie (Motion Pictures Experts Group) |
| .mpeg | MPEG Movie |
| .mpeg1 | Multiplexed MPEG-1/2 Format |
| .mpeg2 | Multiplexed MPEG-1/2 |
| .mpeg4 | MPEG-4 Video Format |
| .mpega | MPEG Sound |
| .mpf | Microsoft Design Gallery Format |
| .mpg | MPEG 1 Video File Format |
| .mpg2 | MPEG-2 Video Format |
| .mpg3 | MP3 Audio File For Mac |
| .mpg4 | MPEG-4 Video |
| .mpga | Mpeg-1 Layer3 Audio Stream |
| .mpgindex | Adobe MPEG Index Format |
| .mpgv | MPEG-2 Video |
| .mph | Microsoft Publisher |
| .mpi | InstallJammer Project Format |
| .mpj | MINITAB Spreadsheet Project Format |
| .mpk | Painkiller Overdose Game Map Format |
| .mpkg | Meta Package Format |
| .mpkt | MOPEKS Trial |
| .mpl | AVCHD Playlist Format |
| .mplf | CodeWarrior Library |
| .mpls | Blu-ray Movie Playlist Information Format |
| .mpm | Corel WordPerfect MathPlan Macro Format |
| .mpnt | MacPaint Image Format |
| .mpo | CIPA Multi-Picture Format |
| .mpp | Microsoft Project Plan Format |
| .mppx | Microsoft Project Project |
| .mppz | MagicPlot Project Format |
| .mpp_ | Microsoft Project For Mac Plan |
| .mpq | Blizzard Entertainment Archive |
| .mpqe | Blizzard Encrypted Game Data |
| .mpr | Visual FoxPro Generated Menu Program |
| .mprj | Maschine Project |
| .mps | Microsoft Pocket Streets Map Format |
| .mpsub | Subtitle Format |
| .mpsy | CodeWarrior Debug Symb |
| .mps_ | MPW Shell |
| .mpt | Microsoft Project Template Tile |
| .mpu | MPEG Layer 3 Audio Format |
| .mpv | MPEG 1 Video Format |
| .mpv2 | MPEG II Video Format |
| .mpvf | CompeGPS Land Fast Vector Map |
| .mpw | Microsoft Project Workspace Format |
| .mpwd | MacWrite Pro |
| .mpwr | MacWrite Pro |
| .mpx | Microsoft Project Export Format |
| .mpz | Miradi Project Format |
| .mpzip | Multisim Pack Format |
| .mp_ | Mobile Phone Sound Format |
| .mq4 | MetaTrader Custom Indicator Format |
| .mqh | MetaTrader Trading Terminal |
| .mql | MetaTrader Indicator |
| .mqo | Metasequoia 3D Image Format |
| .mqt | MetaQuotes Language 4 MQL4 Template |
| .mqv | Sony Movie Player File Format |
| .mraw | Photron Camera RAW Image |
| .mrb | C++ Multiple Resolution Bitmap Graphic Format |
| .mrc | MIRC Script Format |
| .mrd | MathRevolt Infinity Document |
| .mrec | MADRIX Record |
| .mrf | Macintosh Font |
| .mrg | MySQL Reference Format |
| .mrimg | Macrium Reflect Disk Image Backup |
| .mrk | DPOF Digital Print Order Format Auto Print Order Format |
| .mrl | MRLR Multimedia Retrival Markup Language |
| .mrm | Gothic 2 |
| .mrml | 3D Slicer Scene Description Format |
| .mro | SharpEye Music Reader |
| .mrp | Infinity Solution Plot |
| .mrs | Corel WordPerfect Macro Resource Format |
| .mrt | Microsoft Visio 2010 Installation Archive Format |
| .mrv | MarvinSketch |
| .mrw | Minolta Dimage RAW Image Format |
| .mrxs | MIRAX Virtual Slide Format |
| .ms | 3D Studio Max Script Source Code |
| .ms-tnef | Microsoft Transport Neutral Encapsulation Format |
| .ms1 | VirtualBus Map Format |
| .ms10 | NI Multisim V10 Circuit Design Format |
| .ms11 | NI Multisim V11 Circuit Design Format |
| .ms2 | SEQUEST Ms2 |
| .ms3d | MilkShape 3D Model Format |
| .ms7 | NI Multisim V7 Circuit Design Format |
| .ms8 | NI Multisim V8 Circuit Design Format |
| .ms9 | NI Multisim V9 Circuit Design Format |
| .msa | Magic Shadow Archiver Atari Disk Image |
| .msb | The Bat! Format |
| .msc | Microsoft Management Console Control Format |
| .mscg | Microsoft Clip Art Gallery For Mac |
| .mscr | Rename Master Scrip |
| .msct | MOPEKS Script |
| .mscx | MuseScore Music Score Format |
| .mscx, | MuseScore Music Score Backup |
| .mscz | MuseScore Compressed Music Score Format |
| .mscz, | MuseScore Music Score Backup |
| .msd | Map Service Definition Format |
| .msdev | Microsoft Visual C+ Make |
| .msdl | Manchester Scene Description Language |
| .msdm | Microsoft Windows |
| .msdvd | Microsoft Windows DVD Maker Format |
| .mse | 3D Studio Max Encrypted MAXScript Format |
| .mse-installer | Magic Set Editor Installer |
| .msf | Mozilla Thunderbird Mail Summary Format |
| .msg | Saved Email Message |
| .msgr | Microsoft Graph 5 |
| .msh | MASH Microsoft Agent Script Helper Format |
| .msha | Microsoft Help Library Help Manifest Format |
| .mshc | Microsoft Help Container Format |
| .mshdb | Ministry Scheduler Pro Database |
| .mshi | Microsoft Help Index Format |
| .mshxml | Microsoft XML Typedata |
| .msi | Microsoft Windows Installer Installation Package |
| .msie | Microsoft Internet Explorer For Mac HTML |
| .msif | MyLabel Designer Deluxe Label Format |
| .msil | Microsoft Intermediate Language |
| .msj | MicroSurvey CAD Temporary |
| .msk | Corel PaintShop Photo Pro Mask Image Format |
| .mskin | Maxthon Skin |
| .mskn | MediaMonkey Skin Format |
| .msl | Miranda IM Smiley Definitions |
| .mslz | Archive |
| .msm | Windows Installer Merge Module |
| .msmessagestore | Windows Mail Message Information Database |
| .msn | Microsoft Windows Network Related Format |
| .mso | Microsoft Organization Chart Chart Format |
| .msof | Microsoft Office For Mac |
| .msp | Windows Installer Patch Format |
| .mspx | Microsoft XML-based Web Page |
| .msrcincident | Microsoft Windows Remote Assistance Request Format |
| .mss | Miles Sound System DLS 1 Sound Format |
| .msstyle | Windows XP Unsigned Style |
| .msstyles | Microsoft Windows Resources Themes Luna Format |
| .mst | Windows Installer Transform Script Format |
| .mstat | SAM Domain Output |
| .mstt | Prosa Minispecification |
| .msu | Microsoft Update Standalone Package Format |
| .msv | Sony Memory Stick Compressed Voice Files |
| .msvc | Microsoft Visual C++ Compiler Makefile |
| .msw | Microsoft Word 5 Document Format |
| .mswd | Microsoft Word For Mac Document |
| .mswk | Microsoft Works For Mac |
| .mswmm | Microsoft Windows Movie Maker Project Format |
| .msx | Age Of Empires II Saved Game |
| .msym | ArchiCAD For MAC Geometric Description Language |
| .msz | MediaMonkey Skin |
| .ms_ | Microsoft Windows Winhelp Compressed |
| .mt2 | MadTracker 2 Module Format |
| .mt9 | MT9 Audio Format |
| .mta | Samsung AllShare Metadata Format |
| .mtb | MediaTracker Database Backup |
| .mtc | MediaTracker Database |
| .mtd | Musicnotes Digital Music Sheet Format |
| .mtdd | MEDITECH Document Definition |
| .mte | MadTracker Envelope Gile |
| .mtf | Motorola Theme Format |
| .mtg | Making The Grade |
| .mth | Derive Math Format |
| .mthd | MOPEKS Method |
| .mti | MadTracker 2 Instrument Format |
| .mtiff | Multi-page Tiff |
| .mtk | MPU-401 Trakker |
| .mtkey | ProDAD Heroglyph License |
| .mtkt | MTK GPS Receiver Data |
| .mtl | OBJ Material Format |
| .mtm | MultiTracker Music Module (MOD) Format |
| .mtml | Meaningful Text Markup Language |
| .mtn | Match! Database |
| .mto | FastCAM MTO Data |
| .mtp | Minitab Portable Worksheet Format |
| .mtr | RealFight Radio Control |
| .mtra | MascotCapsule Resource |
| .mts | AVCHD MPEG-2 Transport Stream Format |
| .mts1 | MPEG-2 Transport Stream |
| .mtt | Microsoft Messenger Saved Contact Format Format |
| .mtv | MTV Video Format |
| .mtw | Minitab Data Format |
| .mtx | Microsoft Visual Studio Manual Test Text Format |
| .mtxt | MOPEKS Problem |
| .mtz | Compressed MetaStream Scene Format |
| .mt_ | Encore Compressed |
| .mu | Corel Quattro Pro For DOS Menu Definition Format |
| .mu3 | Myriad Packed Musical Score |
| .muc | Music Collector Collection Data |
| .mud | Textease Multi User Database |
| .muf | Alpha Five Access Control Format |
| .mug | Hanes T-ShirtMaker Document |
| .mui | MultiLanguage Windows Resource Format |
| .muimanifest | Microsoft Windows Multilingual User Interface |
| .mui_cccd5ae0 | Hid User Library |
| .mul | Ultima Online Game |
| .mulib | Adobe Muse Exported Library |
| .mult | SAM Alignment Output |
| .mum | Windows Vista Update Package Format |
| .mup | Music Publisher Data Format |
| .mus | Finale Music File Format |
| .mus10 | Audio |
| .musa | Aleph One Music Format |
| .muse | Adobe Muse Project Format |
| .musx | Min‐U‐Script Xpress Transcript Data |
| .mut | Integrative Genomics Viewer Mutations List |
| .mux | TrackMania Music Format |
| .muz | MUZ Audio Format |
| .mv | IRIX Command Compressed Movie Format |
| .mv1 | Video |
| .mv4 | Apple QuickTime Video |
| .mv85 | Adobe Director For Mac Movie |
| .mv93 | Adobe Director For Mac Movie |
| .mv95 | Adobe Director For Mac Movie |
| .mva | Microsoft Setup Archive |
| .mvb | Multimedia Viewer Book Format |
| .mvc | Sony Digital Mavica Photo Image Format |
| .mvd | Movie Edit Pro Video Format |
| .mvdx | MindView MindMap Archive |
| .mve | Interplay Video Format |
| .mvex | Muvee AutoProducer Unicode Document Format |
| .mvf | AutoFlix Stop Frame |
| .mvg | ImageMagick Proprietary Vector Graphics Format |
| .mvi | Autodesk AutoCAD Movie Command Format |
| .mvl | Medison 3D Volume Data |
| .mvm | MAGIX PhotoStory On DVD Slideshow |
| .mvp | Movie Edit Pro Video Project Format |
| .mvr | IBM HotMedia Multimedia Format |
| .mvs | MusicMatch Jukebox Visualization Format |
| .mvt | Ultimate Wish Lists Template |
| .mvv | AVS Media Player MPEG Video |
| .mvw | Saber LAN Log |
| .mvx | Multimedia Fusion Movement Extension Format |
| .mvy | MAGIX Video Easy Project Format |
| .mv_ | Magix Movie Edit Pro Movie Backup Format |
| .mw | Maple Worksheet Format |
| .mw2 | MicroWorlds Logo Activity |
| .mw2d | Apple MacWrite |
| .mw2s | MacWrite II Model |
| .mw4 | MechWarrior Game Structure File Archive |
| .mwand | Apple GarageBand MagicMentor Tepmplate Format |
| .mwav | Extended WAV |
| .mwb | MySQL Workbench Database Models |
| .mwc | Make Project Creator Input |
| .mwd | Mariner Write Document Format |
| .mwdp | CodeWarrior Debugger |
| .mwe | OpenArchitectureWare Workflow |
| .mwf | MapGuide Format |
| .mwi | Medlin Payroll Software Invoice Layout Information |
| .mwii | MacWrite II Text Document |
| .mwk | MusicWrite Music Score |
| .mwlic | MoneyWell License Information Format |
| .mwp | Lotus Word Pro 97 Smartmaster Format |
| .mwpd | MacWrite Pro Document |
| .mwpp | MacWrite Pro Document |
| .mwpr | MacWrite Pro |
| .mws | Maple Spreadsheet Document Format |
| .mwt | MetaStock Stock Analysis Template |
| .mwx | Autodesk MapGuide Author Map Window XML Format |
| .mx | Matlab Common Matrix Routines Format |
| .mx1 | Coucoucircus.org Audio Temporary |
| .mx2 | MasterCook Recipe |
| .mx3 | Mixcraft Project Format |
| .mx4 | Mixcraft 4 Audio Format |
| .mx5 | Mixcraft 5 Audio Format |
| .mx5template | Mixcraft Audio Project Template Format |
| .mx6 | Mixcraft 6 Audio |
| .mxad | Mandelbrot Explorer All Data Format |
| .mxaddon | Maxthon Addon Format |
| .mxc | ArcView Geocoding Index For Read-write Coverages |
| .mxc2 | MAGIX Music Maker Cache |
| .mxc3 | Magix Photo Manager Thumbnail Cache |
| .mxcs | Mandelbrot Explorer Colour Scheme Format |
| .mxd | ArcGIS Map Document Format |
| .mxdic | Maxthon Dictionary Format |
| .mxdl | Maxthon Incomplete Download |
| .mxe | Corel Quattro Pro Startup Macro Format |
| .mxf | Material Exchange Format |
| .mxfd | ABBYY Form |
| .mxfr | Mandelbrot Explorer Fractal Region Format |
| .mxg | Miinoto Exchangeable Group Format |
| .mxi | Adobe Dreamweaver Extension Manager Format |
| .mxit | MXit Data |
| .mxl | Compressed MusicXML Music Notation Format |
| .mxm | MixMeister BPM Calculation Format |
| .mxmf | Mobile XMF Format |
| .mxml | Adobe Flex Interface Component Format |
| .mxn | Miinoto Exchangeable Note Format |
| .mxp | Adobe (Macromedia) Extension Package Format |
| .mxprj | Maschine 2.0 Project |
| .mxs | Maxwell Render Scene Definition Format |
| .mxsd | IBM WebSphere Message Definition |
| .mxskin | Maxthon Skin Format |
| .mxt | ArcGIS ArcMap Map Template Format |
| .mxv | MAGIX Movie Edit Pro Video Format |
| .mxz | Maximizer Data |
| .my3D | My3D Tools Exported |
| .myapp | Microsoft Visual Studio Application XML Format |
| .myb | MYOB Data |
| .mycolors | Stardock MyColors Theme Format |
| .myd | MySQL Database Data Format |
| .mydocs | Send To Format |
| .mye | MYOB |
| .myi | MySQL Database Index Format |
| .myl | MyLogo Maker Image |
| .myo | MYOB Data |
| .myob | MYOB Data |
| .myox | MYOB Data |
| .myp | Warhammer Online: Age Of Reckoning |
| .myr | Myriad Music Format |
| .mys | Vineyard Captured Video Format |
| .myv | Vivaldi Studio Score |
| .mz | Mozart Compressed |
| .mz2 | Maze-solver MZ2 |
| .mzb | MegaZeux Board |
| .mze | Maze Creator |
| .mzf | MediaZip Archive |
| .mzp | Autodesk 3D Studio Max MAXScript Zip Package |
| .mzt | MOZART Template |
| .mzv | Viewpoint Media Player ZoomView Titles |
| .mzz | Microsoft .NET Framework Installation Package Format |
| .m_p | Pro/ENGINEER Temporary |
File extensions are not normally displayed to users. To change this, go to Control Panel, select Appearance and Personalization and Folder Options. Next, select the View and find the option "Hide extensions for known file types". The option should be deselected (cleared) and confirmed with OK.
