Backbox Linux

Backtrack has a new arch enemy!
BackBox is a Linux distribution based on Ubuntu. It has been developed to perform penetration tests and security assessments. Designed to be fast, easy to use and provide a minimal yet complete desktop environment, thanks to its own software repositories, always being updated to the latest stable version of the most used and best known ethical hacking tools.The last edition of BlackBox is based in Ubuntu 11.04.Also they added 3 new categories:

1. Vulnerabilty Assessment
2. Forensic Analysis and
3. VoIP Analysis

You can find it here:
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Official Website