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.
M4R is a filename extension for AAC format, which is developed by Apple Inc. It is typically used to save custom iPhone ringtones from Apple iTunes. M4R can only be created from iTunes purchased songs and is usually DRM protected. It can open on iTunes, VLC Media Player, Apple QuickTime Player, and more.