Russix is a Slax based Wireless Live Linux.

It has been designed to be light (circa 230Mb) and dedicated purely to wireless auditing.

It is not a script kiddy phishing tool and as such, while it will allow you to break a WEP key in 6 key strokes and conduct an "Evil Tiny Twin" attack in less than 5, it will not let you become the latest version of Barclays Bank.
Russix evolved from an internal UK Military Wireless auditing tool (debian based) which russ had developed while working for them as a penetration tester. He had tried to mod Backtrack with extra drivers and the aircrack-PTW tools but hit too many 'issues'.

Furthermore, Backtrack is over 600mb; not that we have an issue with Backtrack, it is a cool tool, it just had too much stuff we didn't need.