Very impressive effort from a 15 year old(!) coder porting Quake to HTML5/WebGL. Looks like a line-by-line hand coded port rather than an automated emscripten build, which is even more exciting! Runs very smoothly as well, though it currently lacks niceties like mouse lock and fullscreen.
Thanks! Mouse lock will be added when fullscreen is not required for it in Firefox. Element fullscreen looks hard to implement in Quake, but F11 fullscreen works well (however it doesn't enable pointer lock).
Yeah, it's just sad. When Google released our port of Quake2 a couple of years ago, with the demo assets, we couldn't get rights to host it. Mozilla also tried to host an emscripten powered port and got a takedown notice.
To me it's bizarre that a company won't allow use of almost 20 year old demo assets, when a) people can download them anyway and b) it's free advertising for them. Just MHO.
The port is completely safe from ZeniMax. There are no Quake resources in its GitHub repository. The host is, however, playing with danger by hosting registered (!) version with 2 mission packs and the soundtrack.