Kwiuu

Not what you want probably but Tangled.sh

tightly-knit
social coding. tangled is new social-enabled git collaboration platform built on atproto. we envision a place where developers have complete ownership of their code, open source communities can freely self-govern and most importantly, coding can be social and fun again.

Just want to mention this; can't contribute much to the conversation other than wanting to mention this cool repo on github called OSSU. It's a community of peeps linking free and paid resources life a university curriculum. They have other topics too like advance math, I think?