currently i am porting Kraken, the fantastic A5/1 cipher cracker to win32/x64.
it seems that i am done with most of the steps.
it starts, cracks the keys, supports ATI cards as the linux version does and is even able to run as a multi-client server application.
i also added support for older cards like the Radeon HD 3870 which will speed up the key search by maybe 10% depending on your HDD setup.
unfortunately its no GPL or even a more free license like MIT or BSD.
so i may not publish my changes. instead i will try to get them added to the original repository.
since i also changed a lot (!) in the internals of kraken, i am not sure if it will get added :)