Use the playlist.fetch method call to fetch XSPF playlists. XSPF is a web standard for sharable playlists, and XSPF libraries are available in several languages. playlist.fetch takes a `lastfm' protocol URL as an argument; this identifies the playlist you're requesting. The following protocol url schemes are currently supported:
Album Playlistslastfm://playlist/album/<album_id>
User Playlistslastfm://playlist/<playlist_id>
Tag Playlistslastfm://playlist/tag/<tag_name>/freetracks
If you'd like to add play links to your playlist you can link to the Last.fm track page (which will be present in the XSPF extension node), appending '?autostart' to the URL.