I would be shocked if they weren't using a test suite, especially given all the platforms and devices Linux supports. POSIX has a test suite, and there are several Linux test suites [1], [2]. Although, I would think that an architecture port is fairly straightforward. It's reverse-engineering and writing all the device drivers, but devices generally have a well-known interface (and, therefore, presumably tests). The OpenGL drivers are being tested against the official OpenGL test suite.

Of course, there are no guarantees that it runs correctly. Probably doesn't, given that even Apple and Microsoft's software don't run correctly, either. But saying software doesn't run perfectly in all cases is almost tautological.

[1] https://github.com/phoronix-test-suite/phoronix-test-suite

[2] https://github.com/linux-test-project/ltp

And this also has implications for security.

Fair enough, I suppose I could be overly optimistic. I just figure it's garnered enough interest that even if there's turnover in the team somebody will carry the torch. Especially since Apple seems to be actively tolerant if not even supportive of the project.