MediaMonkey 4 supports:

 - Playback of M4A/M4B files via Windows 7 codecs.  See:

   http://msdn.microsoft.com/en-us/library/windows/desktop/dd742784%28v=vs.85%29.aspx

 - Playback of M4A/M4B/M4P/ALAC via Quicktime.

 - Encoding/decoding of M4A/M4B files via the MediaMonkey Codec Pack (purchased separately)



MediaMonkey 3 supports  Playback of M4A/M4B/M4P/ALAC via Quicktime, and encoding/decoding

of M4A/M4B files via the MediaMonkey AAC Encoder Plug-in (purchased separately)



Note that the MediaMonkey Codec Pack and AAC Encoder Plugin, can play AAC audio 

files, and convert and analyze all AAC tracks that don't have DRM, but do not supported DRMed 

content (i.e. .m4p files cannot be converted or analyzed). 



MediaMonkey 2.5 does not include AAC support at all, though playback support can be added 

through the use of third-party plug-ins. This support is available using the following plug-ins:

 1. MP4 input plugin. This supports unprotected .m4a and .mp4 files and can be downloaded from:

     http://www.free-codecs.com/download/MP4_input_plugin_for_Winamp.htm

 2. Winamp MP3/MP4 input plug-ins. The MP4 plugin supports unprotected .m4a and .mp4 files

     and is included with Winamp 5 and can be copied to the MediaMonkey plug-ins directory

     (both libmp4v2.dll and in_mp4.dll must be copied). The MP3 plug-in supports AAC files.

     One of our users has conveniently hosted these files at:

     http://home.tiscali.be/ruben.castelein/filestore/in_mp3.dll

     http://home.scarlet.be/

     http://home.tiscali.be/ruben.castelein/filestore/in_mp4.dll

 3. M4P input plugin. This supports protected iTunes content and can be downloaded from:

     http://www.free-codecs.com/download/M4P_input_plugin_for_Winamp.htm

Note that AAC playback in MediaMonkey 3/4 can fail if you've performed an upgrade from 

MediaMonkey 2.x to MediaMonkey 3.x/4.x, and the AAC plugins installed for MediaMonkey 2.x 

have not been removed --these may interfere with the native AAC plugins available for 

MediaMonkey 3.x/4.x.