AMD released specifications which were used to develop some code although
this is basically a wrapper around a proprietary component. This is not
acceptable behavior here and can be viewed as more or less a public relations
stunt than something helpful to the free software community.
Intel is the only major company supporting an acceptable free software driver
which supports 3d acceleration.
I will mention that there is a reverse engineered driver entirely created by
a third party project which supports older NVIDIA chipsets. This might be OK
to use too although many/most here would not recommend purchasing such a
card. The reason being is that reverse engineering unnecessary when companies
cooperate and is a a significant amount of work. Why should free software
users support a company hostile to them?
That said we do stock one such desktop card @ libre.thinkpenguin.com.