This article hasn't been updated for over a year.
XMPP (formerly known as Jabber) is a messaging protocol similar to Skype, Facebook Messenger and the late Windows Live Messenger. What makes XMPP so special is that unlike these other protocols, it supports what the XMPP community calls federation. People on servers that support federation are able to communicate with people on other servers, even if they are managed by a completely different company.
Federation solves one of the biggest problems that other messaging systems face: you can’t be forced to use a certain app because most of your friends use it. When a new service turns out to be better, you can simply create an account there and take your contacts with you. Even though your contacts stay with the old service provider, thanks to XMPP federation you can continue to talk to them as usual. (Well, they would have to add your new account to the contacts list, but after that it simply works.)
Sounds familiar? E-mail works the same way!
Support for XMPP is declining
It looked like XMPP would become the next big messaging protocol. Even big players like Google, Microsoft and Facebook used XMPP for some or all of their messaging applications. Over the last few years this trend came to a halt as some of the bigger communities dropped support. Google replaced Google Talk (which supported federated XMPP) with Google Hangouts, using a proprietary protocol. Around the same time, Facebook shut down the XMPP interface to their chat network.
While hundreds (if not thousands) of XMPP networks remain, the total number of users is very small. Most people are using large proprietary platforms like Whatsapp, Facebook Messenger or iMessage. This has removed the major use case for XMPP: a chat protocol is useless if there is nobody to communicate with.
My personal XMPP server was no different. I was the only user and my contact list shrank to only 2 friends. Not to mention the fact that I usually connected them through other means. Logs revealed that my server was communicating with other servers more than I actually sent useful messages. It has begun, computers are talking!
Devices and apps
As XMPP is an open protocol there’s a pretty big choice when it comes to applications. I’ve been using Gajim and Pidgin on Linux, Conversations on Android and the built-in Messages app on macOS. Due to lack of contacts these apps weren’t used much, but running pretty much all the time. Especially on mobile this becomes a problem: XMPP is another connection to keep alive, eating my already tormented battery. Therefore I sometimes disabled these apps when I needed battery power for other things.
I still think XMPP is, by far, the best chat protocol we have today. But sometimes (or most of the time?) technology is not enough. People have to actually use the protocol for it to be succesful. It’s hard to stop using something that you want to become the next big thing. But the time has come to see that XMPP is not that thing. I have shut down my XMPP server.
One day, people will understand that federation is necessary.