It'll be interesting to see how well this turns out; I remember hearing about opengraphics.org a few years ago, which seems to have reached prototype hardware stage and then died. GPUs are still one of the most closed parts of a computer, so this is certainly a step in the right direction. There's also this, which is only VGA-compatible, but similarly hasn't had much success: http://wacco.mveas.com/
This seems to be the code from the "Open Source Graphics Project" Kickstarter that ran last year. They didn't get anywhere near the $200K goal for 2-D, much less the $400K goal for 3-D. Glad to see that it's getting out there anyway.
It could also (really) use some screenshots. But perhaps that's way too early, although there's talk about results in terms of tests passing and failing. I imagine that for a GPU, some of those would involve some type of rendering.
...but there's this complete PC-on-an-FPGA, including a VGA-compatible controller: http://zet.aluzina.org/index.php/Zet_processor