@waifu I I tried Tigase but the version they gave in the repositories is buggy. Then I tried ejabberd, it is a bit complicated with too many options, but it is powerful and I think is worth the effort. It has the option to manage multiple domains and it is not "so" complicated to set up the clusters (even thou I haven't succeeded in that), but yes, it has too much documentation and I think I will take the time to read it calmly.
@waifu @icedquinn I didn't like Snikket site either