Minecraft Snapshot 13w22a

Are you ready for some bugfixes? There is a whole plethora of them! Poring over many of the bugs introduced in recent Snapshots, Mojang has been hammering them all out, one by one! While a new resource system is in development, it is not currently available for testing.

Source:

http://www.moddb.com/news/minecraft-snapshot-13w22a