Originally Posted by LubosD
Releasing internal documentation doesn't cost money or much time.
That is certainly untrue. You can be sure no such documentation to straight out write a driver exists even within NVidia. The drivers are surely developed on some base documentation, and then a lot of talks between the driver writer and the chipmaker standing by the coffeemaker. Not to mention the sessions they spend debugging at a hardware level. Or the exchange between the Linux and the Windoze teams.
ATI documented the cards up to Radoen 9200 for the DRI project. Even this documentation is not sufficient as such. You can read a lot of bitchingwhiningcomplaining about it on the DRI mailing lists.
From my work experience as a programmer I would even say the reverse of what you say is true. It is probably easier to come up with a good enough piece of software than with documentation for the underlying mechanism to write all possible pieces of software on top.
Personally I am losing patience with NVidia. I was swallowing them not documenting the 3D cards. But now that they use the same argument on SATA and GbE chips it is obvious that this is is rooted in attitude.