a list of all rooms, recently active rooms first
For MathJax see https://meta.stackexchange.com/a/220976. Related rooms: Mathematics (https://chat.stackexchange.com/rooms/76340/jee-maths-problems) and Chemistry (https://chat.stackexchange.com/rooms/74807/jee-high-school-chemistry-problems).
Lugar de chateo para los grammar punkies de Spanish Language https://spanish.stackexchange.com/
A place to chat about the Bitcoin Stackexchange, cryptocurrencies in general, and anything else that might be up.
For PPCG users to discuss and play video games and board games. Discord server: https://discord.gg/FfwjCFE
For any discussion concerning linear, abstract or even elementary algebra
Скорая помощь SVG. Спецификация на русском https://ru.stackoverflow.com/a/825963/28748
Where the community chips in to help clean up http://scifi.stackexchange.com - bring safety gloves and Marshal badges
Game theory, decision making, networked systems, mechanism design
For discussion about programming, math, linguistics, science, and related topics. Not about PPCG (the site itself) or golfing.