ID:1986301
 
I know BYOND still supports telnet, but I was digging around in the program files and found references to IRC (Internet Relay Chat).

"C:\Program Files (x86)\BYOND\cfg\irc.dms"

Did byond seriously have IRC support at one point or was that just to create an IRC server?

http://www.byond.com/docs/guide/app4.html
It was possible to connect to IRC servers using Dream Seeker.
Still is, actually, although DS lacks some basic features that make it unusable.
Right, the feature was depreciated over a decade ago and there's no real reason to bother with it any further.