mp3PRO: http://www.mp3prozone.com/
MPEG (Moving Picture Experts Group): http://www.chiariglione.org/mpeg/
MPEG Industry Forum: http://www.m4if.org/
MSN (Microsoft Network): http://www.msn.com/
MSN Encarta (en anglais): http://encarta.msn.com/
MSN Encarta (en français): http://fr.encarta.msn.com/
MSN Music: http://music.msn.com/
MSNBC (Microsoft Network Broadcasting Corporation): http://www.msnbc.msn.com/
Mutopia Project: http://www.mutopiaproject.org/
MySpace: http://www.myspace.com/