[Cthulhu_]

Quake's engine is open source and for example nvidia used it in some more recent tech demos, although this one's for Quake 2: https://www.nvidia.com/en-us/geforce/news/quake-ii-rtx-v1-2-...

[koverstreet]

Quake 2 was when they added multi-colored lighting - it's really aged well.