The GRP Playlist is a Noatun playlist plugin. It is a playlist inspired by ZInf, in which you can organize your multimedia files in groups based on the files meta information (Artist, Album, etc)
Currently in very early stages of development! (But pretty usable)
It's made and tested on GNU/Linux, but i think it can run on whatever platform that KDE and Noatun runs
The only required thing is KDE3.2 and, of course, Noatun. To compile you also need the development headers of KDE and Noatun.