The CPS2Shock team, led by the great Raz, produces XOR files that alow for the decryption of games that run on the extreamly well known CPS2 System.

Raz (or most anyone else working on CPS2 emulation) are not experts in the archectures of CPS2 or QSound. Both Capcom and QSound Labs have NDA's for that kinda stuff, so they have not now (or in the past) said anything. Everything has been done painfuly slowly through reverse-engneering. Proof of concept: Raz assumed the QSound chip ran at 4-6 MHz, when it really ran at 8 MHz. Anyone who really knew anything about QSound would not make such a stupid mistake.

Finally, they are only relaseing old CPS2 games (Only upto December of 1997) as MANY CPS2 games are still in arcades being played (The VS Series comes to mind), and Capcom is still relasing new games for the system (Such as 'Progear no Arashi'), so to relase newer games would be a nasty blow to the already near-death arcade culture.