oh yeah, IRC also gives you utter lack of customizability due to all the existing IRC servers being a teeming pile of crufty C code, all derived from the original dating back to the very early 90s, and none exhibiting much design clue.
Because NFC's codebase doesn't suck, it now supports authentication to a database (including setting admin levels there), database-backed "chatmail" (messages to offline users will be delivered when they come online), database-backed per-room access control, database-backed per-user custom welcome messages, [optional] deflation of message packets, and more. These are all features I added in the last year, with the exception of the first.
Good luck getting a C-coded irc server to even talk to your database. :)