hi juto,
no nv is the libre drivers for nvidia... ati I didn't see any project around but I don't use ati cards... I try not to use ati & nvidia and most of my problems are resolved, there are plenty of others video cards with libre drivers support...
i couldn't get the nv driver running on my machine for longer than 2 minutes without graphics problems ... otoh, the nvidia drivers are easy to install, use and rock-solid i don't see any problems with using a closed-source driver, if there is no open source driver available / usable ... it's better than having no driver at all (which unfortunately is far more common in the linux world).
cheers... tim