Keep Circulating the Tapes: Inquisitor had a supported lifespan of about six years from 2001-2007, with a lot of material being available in PDF especially post-2004, eventually disappearing along with everything else Specialist Games in 2007. The fact that it was available in PDF means that the material is still circulating and probably will be as long as there's any interest, and there are currently two separate independent games based on it: Inquisimunda combines a lot of its material with the Necromunda ruleset, and Inq28 is the original rules, just scaled down to use centimetres instead of inches, so that it can be used with 28mm miniatures like standard Warhammer 40,000 kits or third party pieces the modeller finds interesting.
