NVIDIA has released some MIT licensed documentation of their hardware interfaces, and it sounds like there is more on the way. This could be a big help to the open source Nouveau driver, although information on re-clocking some of the newer cards to get the most performance out of them is not (yet) available. AMD has long been doing this with their cards, though their releases have been both more complete and more timely. Time will tell if NVIDIA gets to parity with them or not. It is AMD's support of open source that have made me a customer.