Question: how to play xspf files?
Answer: Just open the XSPF file in VLC and then go to the Media > Save Playlist to File option to convert the XSPF file to M3U or M3U8. Online Playlist Creator might be helpful in converting XSPF to the PLS or WPL (Windows Media Player Playlist) format. You can convert an XSPF file to JSPF with the XSPF to JSPF Parser.