WavPack lossless audio compression. Note that, when converting .wav to this format and back again, the RIFF header is not necessarily preserved losslessly (though the audio is).
Dolby Digital film format, developed for encoding audio tracks for films. It supports up to 6 audio channels: left, right, front, rear, upper and lower. Because of this, it allows you to store “3-dimensional” audio tracks. It’s widely used both in movie theaters and by the users themselves for storing audio tracks in film libraries at home.