Nice to see Team Fortress (Quake 1 mod) get a shout out. 23 years later, we've still got a team developing and playing it. https://www.fortressone.org/
I a developer on FortressOne - a still actively developed continuation of the original QuakeWorld Team Fortress. We have an extremely active community with games taking place nightly. It's a testament to Carmack that his code from 1996 is still widely used in 2019.