Actually, it is only necessary to install it on the PC side. It just browses your computer looking for media files (MP3, AAC, WMA, FLAC, Ogg Vorbis, WAV, etc.) and organises it using the ID3 tags (author, album, genre, etc.) or filenames through a http front end.
Quite friendy, it is also GPL and does have multiplatform support (Mac OS X, Windows, and Linux).
All in all, niiiiiiice!