Backtrack 5 R2 finally released with bug fixes, upgrades, and the addition of 42 new tools. Metasploit 4.2.0 Community Edition, version 3.0 of the Social Engineer Toolkit, BeEF 0.4.3.2, and many other tool upgrades. Backtrack added Wiki about Building a Pyrit Cluster, Creating a John the Ripper Cluster, Enabling PAE in BT5 R2 and Installing VMware Player on there page Read Here.
Source: https://thehackernews.com/2012/03/backtrack-5-r2-released-new-kernel-new.html