If they never release the source, including all the fpga verilog files then this is pointless to the open source community.
Edit: actually I just realized my comment is kind of pointless. Even if he released the fpga source code, a thing a lot of projects like these never do, it still wouldn't be possible to reproduce one of these using only free and open source software. This is because the only fpgas that let you program them using open source software and not a locked-down windows-only bloatfuck program that needs an internet connection and licensing are the lattice ice40 fpgas. Tl;dr this can't be fully "open source".
I wonder if it would be possible to make an ice 40 based video card that could still do opengl.
Cinnamon is the only other desktop environment that I can really use besides KDE. To me they're equal in quality. Cinnamon does some things better than KDE, KDE does some things better than Cinnamon. It varies based on how each one is configured in your distro's repository more than anything. KDE on Arch is top notch. Cinnamon on Arch is hot garbage. Cinnamon on Ubuntu is usually really good, KDE on Ubuntu was barely usable last time I tried it.
If you know a lot about desktop environments you could fix either one yourself but I only use them based on which one works better after I download it and configure basic settings.