I care about federation, scalability, robustness, access to past messages (history, as you put it) and disconnected operation (e.g., access missed messages on r

I care about federation, scalability, robustness, access to past messages (history, as you put it) and disconnected operation (e.g., access missed messages on reconnect) -- that sort of thing. Maybe file sharing. The only rich text features I use are: code quoting, and text quoting, and I just don't need those if I'm using a traditional IRC/XMPP client. I don't care about text styling or formatting, or emoticons. IRC is ancient, and pretty much broken, but it still works fantastically well for some things, and I really like having a text-based client to run in a tmux. EDIT: IRC, XMPP, and such, support integration just fine via bots.