This is a proprietary format (with a paid license) developed by Matthew T. Ashland. Sound is stored without any loss, but the format isn’t too common because of license restrictions and because the official codecs works only on the Windows platform.

This is open lossless codecs, developed under the Ogg project. Lately it’s become quite popular: many users wishing to store audio with original quality choose FLAC. This is partly in connection with the fact that codecs uses IDv1 and IDv3 tags – this allows a user to sort an audio collection according to one’s particular tastes, changing the original metadata of the tracks.