I ran one of the biggest EFNet IRC hubs at Texas.Net up until we pulled the plug in '98 due to smurfing attacks. :)
Since then a bunch of friends and I have run a tiny multi-server network after we all moved off the public networks.
Started a new job this past February, and I asked my boss during the interview how we handled inter-person communication since we're scattered all over the country. "We have our own internal IRC server if you know what that is..." I said "THANK YOU JESUS!" and he cracked up.
IRC is definitely still out there and heavily used.
Heh, I set up an internal IRC server for my previous employer; I mostly just got tired of AIM being shitty, and was already using IRC so I set it up (which was a pain, btw! maybe it's easier now?) so we could all use it.
Pretty amusing, too, because it was four people in an irc room, all of whom were also in the same physical room.
> That would be exactly my own reaction if it would ever happen to me. But so far, unfortunately, it was always either Hipchat or Skype.
Both the IBM LTC and Intel OTC maintain internal IRC servers. They aren't used by the entire company, but they're used by those Open Source groups. (Company-wide IM is still Sametime and Lync, respectively, but both of those are usable from Linux with Pidgin.)
Hipchat ain't bad; the place when I got to use it was a 3-week temporary gig for me (they needed additional programmer for emergency fixes). The places where I was actually employed all used Skype, and "bearable" is the best I can say about it.
I think the best solution would be a Hipchat/Slack-like IRC client.
It's being done in a completely backwards-compatible manner - clients have to opt-in to new protocol features so it's more along the lines of incremental improvements.