Is a multimedia container format from Microsoft, which stores video and audio file streams. Distinctive feature is a the lack of information on the coding data. The container defines the structure of the stream so it can, like AVI, contain videos with different codecs, as well as operate during synchronization of streams.
The maud file extension is associated with the Amiga MAUD audio format, developed by Electronic Arts and Commodore in 1985. The MAUD is used for an 8 or 16 bit Amiga sound format. Most likely obsolete.