XSPF Web Music Player is a flash-based web application that uses xspf playlist format to play mp3 songs. XSPF is the XML Shareable Playlist Format. The software is written in Actionscript 2.
The player receives the parameters on the query string, the most important parameter is the playlist_url, that tells the player wich xspf playlist to play, if you leave it blank the player will play a default playlist. These are number of websites that currently use the XSPF Web Music Player