sourga.me is a way to play Sauerbraten in your web browser, made by nyctrennis. Some of you may remember BananaBread, which let you play singleplayer in your web browser, but this project allows you to play multiplayer as well! You can see an overview of how he did it.
Presentation slides: https://docs.google.com/presentation/d/1xafK5-0nxJzBYb1S6yzedo5NlvHtUEoz7Hn2j5kxuIk/edit?usp=sharing
Git repo: https://github.com/cfoust/sour
As of now, Sourga is updated for Sauer 2020 and can play with regular clients . Check it out! https://sourga.me/