http://defense-update.com/products/s/srats.htm
SRATS which stands for "Specialized Reconnaissance Assault and Transport System" evolved from a proof of concept vehicle, utilizing "Rock Crawler" and "Sand Rail" technologies, which are popular with recreational and extreme off-road automotive sports, to produce an off-road vehicle designed to handle extreme terrain conditions. In 2004 DARPA funded the development of two prototype vehicles under a proof of concept demonstration of a small vehicle which would bridge the gap between the soldier and the HMMWV. At AUSA 2007 BAE Systems and the SRATS developer specialty vehicle maker unveiled their cooperation in transforming the militarized rock crawler into serially produced military vehicle, responding to the US Army's interest in fielding thousand of vehicles to support its light brigades and special forces.