Monkey's Audio is a lossless compression format. From
http://wiki.hydrogenaudio.org/index....ess_comparison, it seems its compression is on par with FLAC, but is much slower to decode. Unless this article is out of date and Monkey's Audio has improved its compression, it doesnt appear to have any benefits over FLAC (slightly OT).
Unfortunately that is the extent of my knowledge about this format, especially since FLAC has much greater acceptance/compatilibity.