Minecraft snapshot 13w37b
Snapshot after snapshot. The people at Mojang do a great job in keeping us up to date with both files and new features. The work and for the upcoming 1.7 is almost done and I bet we will have it shortly.
“Snapshot 13w37b has been released, along with a pre-release of 1.6.3. You can select these versions in your launcher, or download the server links below.
We still strongly recommend that you don’t run the snapshots on an existing world if you don’t want to run into chunk errors. There is a known issue with world structures such as Nether Fortresses not transitioning to 1.7 from 1.6, but loading these areas in the new pre-release 1.6.3 and then going to snapshot 13w37b (or later) should fix this.”
Source: https://mojang.com/2013/09/minecraft-snapshot-13w37a/