This is one of the things I'm trying to solve for at https://learnawesome.org . And yes, it is open-source. Need more users to start contributing though.
Feel free to suggest more ideas to make it a vibrant learning community.
This is supposed to refer to "courses" which are structured, project-based peer groups where mentors spend time to evaluate your projects and answer your questions. By compensating them for their time, we can get really high-quality mentors for 1-1 feedback on your learning projects.
The unstructured peer groups (in the Slack channel) are and will remain completely free.