Netjuke

NetJuke is an open-source php/MySQL-based jukebox for your digital music. Basically, it provides a web-browser access to your digital music from any computer on your network. It uses the ID3 metadata to create and maintain a database of artists, albums, genres, and so on which you can search using any standard browser.

I have been using NetJuke since 2004. Unfortunately it doesn't appear to be very well supported (last updated March 2003). One reason I began learning PHP was to be able to fix some of Netjuke's quirks, bugs, and shortcomings.