Never heard of that one. NVK is a brand new open source driver that uses features of the RTX series to reverse engineer Nvidia drivers. According to the project team, those features make it much easier than before, but it limits the scope to RTX series cards and onward.
This is a good discussion: https://old.reddit.com/r/linuxquestions/comments/1cqcnr3/whats_the_difference_between_nvidia_open_source/
Essentially, Nova is a kernel level driver and not user level