Haxe implementation of XSPF ("spiff"), the XML format for sharing playlists.
It is free and open -- No proprietary lock-in.
It is portable -- You should be able to send a playlist to your friend and have it work.
It is well-engineered -- Most playlist formats get the easy things wrong.
Unlike M3U, XSPF is XML.
Unlike SMIL, XSPF is simple.
Unlike ASX, XSPF is open.