Rockbox for the iPod 4G, Color, Nano and Video models all have a very wide range of codec support - MP3, Ogg Vorbis, Musepack, FLAC, AAC, ALAC, AC3 and WavPack are all supported in Rockbox. Additional music playback features include gapless playback and customizable crossfading, as well as a five-band fully-parametric equalizer to fine-tune sound output. iPods also get ReplayGain support for volume level normalization, and a large number of plugins, including games, applications, and "demos" - have some fun when you've got some free time to kill, open files with the text viewer, make use of the stopwatch, view some JPEG photos, or turn your iPod into a desktop clock. Also enjoy On-The-Go playlist creation and adjustment, full file bookmarking support and much more.