APE (Monkey’s Audio) is a lossless audio file format released in 2000 by Matthew T. Ashland. Because it’s a lossless sound format, it doesn’t lose data during compression, unlike other standard formats like AAC, MP3, and Vorbis. However, Monkey’s Audio is available on PC only. To play APE on Mac OS X and Linux, you’ll need a third-party plugin like JRiver Media Center.
AAX (Atom Asset Exchange) is an audio file format for storing sound-based products from Audible Incorporated. Typically, AAX files are DRM protected, although they can be transcoded to other common formats such as MP3 using a licensed program like Wondershare UniConverter.