I usually rely on Backtrack as my security Swiss army knife. However I recently learned of NodeZero Linux (formerly Ubuntu Pentest Edition-PE). Once I give it a full shake down I’ll post a review of how I think it stacks up against BT.NodeZero is Ubuntu based linux designed as a complete system which can also be used for penetration testing. NodeZero uses Ubuntu repositories so your system will be always up to date. The system setup is basic and it’s primarily designed for disk installation and customization as you want.
With NodeZero comes around 300 tools for penetration testing and set of basic services which are needed in penetration testing.