.MAC - MacPaint

.MAF - Microsoft Access Form (filename extension).

.MAK - Makefile

.MAM - Microsoft Access Macro (file extension).

.MAP - Map - linkage editor

.MAQ - Microsoft Access Query (filename extension).

.MAR - Microsoft Access Report (file extension).

.MAT - Microsoft Access Table (filename extension).

.MCS - MathCAD format

.MCW - Microsoft Word for Macintosh (filename extension).

.MDB - Access database

.MDX - Multi-index

.MET - Metafile - OS/2 (file extension).

.MEU - Menu

.MFF - MIDI File Format (filename extension).

.MGF - Micrografx Draw Font (filename extension).

.MI - Miscellaneous (filename extension).

.MIC - Microsoft Image Composer (filename extension).

.MID - MIDI

.MIFF - An ImageMagick file format

.MIL - Group 4

.Mime - MIME (filename extension); the encoding format used by the Multipurpose Internet Mail Extension.

.MME - Mime encoded file (filename extension); the encoding format used by the Multipurpose Internet Mail Extension.

.MMF - Microsoft Mail File (file extension).

.MMM - Macromind animation

.MOD - (For module). A music file format that contains digitized sound samples A .MOD file takes more memory than a MIDI file because a MIDI file contains instructions for making sounds but not the actual sound samples. There are .MOD players for Amiga, PC, and Macintosh computers.

.MOOV - QuickTime movie. This file can be viewed with QuickTime Player.

.MOV - Movie - QuickTime (file extension).

.Movie - QuickTime movie. This file can be viewed with QuickTime Player.

.MOZ - Mozilla - Netscape cache file (filename extension).

.Mp2 - MPEG Layer II compressed audio. This file can be played using QuickTime Player and some other sound players.

.Mp3 - MPEG Layer III compressed audio. This file can be played with QuickTime Player, Real Player, and some other sound players.

.MPE - MPEG (filename extension).

.MPEG - MPEG movie or animation file. This file can be played with QuickTime Player.

.MPG - MPEG encoded file. This file is an MPEG movie, and can be played with QuickTime Player. (file extension).

.MPNT - Macintosh MacPaint

.MPP - Microsoft Project project file (file extension).

.MPT - Microsoft Project template file (filename extension).

.MPX - Microsoft Project export file (filename extension).

.MRK - Markup - Informative Graphics (file extension).

.MSG - Message file

.MSN - Microsoft Network document (filename extension).

.MSP - Microsoft Paint

.MUS - Music (filename extension).

.MVB - Microsoft Multimedia Viewer (filename extension).