I am currently following Codidact with some interest.
Codidact is a work in progress and fairly new, but describes itself as:
A community-controlled, open-source Q&A platform.
Further Information:
- Codidact Blog
- Codidact Wiki on GithubGitHub
- Codidact.org website
- Codidact on GithubGitHub
- Codidact's Network of Sites