[cellio]

Codidact hosts a network of communities, so if you've got a group of people who are enthusiastic about a topic, you can propose it instead of having to host it yourself. Of course, you can also download the code and set up your own, same as with Q2A or Discourse or others, if you prefer to host.

There are differences among all of these platforms (and Stack Exchange) in terms of specific features. I'm not as familiar with Q2A as I am with SE, so it's hard for me to do a detailed comparison, but some things that I think improve Codidact include: more post types (like articles), privileges based on related activity rather than overall points (for example, a pattern of good edit suggestions leads to being able to edit directly), categories, and lots of customization options for communities.