What are the best self-hosted apps you use?

A team messaging and collaboration tool that can be self-hosted. All your data, in your control. :)

This was one of the first things I threw up on my "personal cloud" server. It's great to have your own little Trello-like site without any limitations.

While Github is nice, it's good to have a little more control over your own projects sometimes, and Gitea makes that easy.