Ask HN: What are open source, decentralized, social replacement applications?

Hello,

Following the last trends, I'm starting to be more independant from the "big players". I already got some VPS and domain name, and use docker to host an email server (because... well... docker is far easier to deploy... and even to migrate to another server).

I'm using whatsapp... but it looks like I may have to leave it soon. And I got no FB nor twitter (but I miss it).

So I'm looking for social alternatives, open source, decentralized, self-hosted replacements.

Until now, I found:

- Matrix/Riot to replace whatsapp/IRC - Mastodon to replace twitter - Diaspora (?) to replace FB

What do you think of these? Pros/Cons? Are the products "simple enough" and "strong enough" to ask to my non-geek friends to move on my server?

Or is there better, with more users, more stable alternatives ?

Thanks a lot for your advice and help! :-)