Mee2 is a fully customizable, open-source Discord bot with a web interface to control it. It supports plugins and is heavily customizable. Mee2 is forever free and licensed under GNU V3.
Mee2 is still actively maintained, but it's not yet ready for public use. Pull requests are welcome. You can find the latest version on our Gitea repo: https://git.nazev.eu:8443/