[usrusr]

IRC, usenet? Even email is usually implemented that way: few end users run their own SMTP servers in the basement.

They have one thing in common: nobody is polishing the brand, nobody is A/B-optimizing addictive properties, there is no startup success story in which users can feel included, rooting for their network of choice.

Oh, and changing a federated system not only requires unanimous decision, it requires unanimous investment. Did the protocols i mentioned feel a bit dated? Might be because of that.

[TeMPOraL]

I purposefully didn't mention IRC in a parallel comment because I don't see how it is federated. You always connect to a particular server and stay within its bounds; you don't get the shared space handled by multiple servers that are abstracted away. Or simpler, you say "I'm hanging out on channel #x on freenode", or "on QuakeNet", not "on IRC".

As for the rest of your comment, I agree.

[usrusr]

The isolation level you speak of is between networks, not between servers. This distinction might seem a little arbitrary since no centralized system of relevance is running on a single server either, but the key difference is still there: in the larger irc networks, the different nodes that form it are run by different organizations.

Splits are a possibility in any federated system and in systems with nonhierarchical, unique naming, any merge requires some amount of namespace violence proportional to the duration of the split.

[spc476]

I seem to recall that when IRC first started, there was only one "network" and that it was a Big Thing when a second IRC network started up.