Ejabberd
Installation
You can build from source, but the repo doesn't even have branches for releases (just tags in master). Plus there are a lot of deps that I'd have to solve. Erlang, ewww.
You can also download the DEB from here.
But Ubuntu has it, so unless that doesn't work out, let's go with that. Only 52 packages (FFS!).
sudo apt install ejabberd