The term "Surfing the Web" is different to the phrase "Chatting on mIRC".
OK, I'm aint surfing anything, neither is it a web.
The phrase was coined from the fact, you could move around the mase, that is called the internet, freely, and without restirction (to a point).
It's all the same, when it comes to putting www in front on an address. The fact that it's there, serves no purpose what so ever. Allthough, it does make for a standard, even if a company doesn't attach the server to the plain domain name (eg egghelp.org, rather then
http://www.egghelp.org).
"Chatting on a mIRC server" is, however, different.
And for proof. Do you hear people talking about "Surfing the Internet Explorer", or "Surfing the Opera" (get the point).
Look at Yahoo!, Geocities and many of the oither chat sites, that do not use a RFC complient IRC server. People still called these IRC chat rooms (another thing, that should only be "IRC rooms").
"Chatting on IRC" and "Surfing the Web" are phrases, rather than names. "Internet Explorer" and "mIRC" are software names, of which, there are several different peice of such, that can be used to connect and do, "Surfing the Web", or to "Chat on IRC".
It's all in the context.