http://www.tunewithcrome.com/ is where you can download chrome, problem is, its obd1 only though, the same concept needs to be applied to our cars (obd0 cars right?)
check out
http://forum.pgmfi.org/index.php, there's probabably something to be found there that can easily be applied to our 944's.
i'll do some research and see if there's a program that's pretty much ready to use for our cars.