JIS is another name for ISO-2022-JP. JIS/ISO-2022-JP is the "real" Japanese encoding, Shift-JIS is Microsoft's bastard version of it. Or that's how I've understood it. And I still have no idea which one is preferred in IRC - with AppLocale it "just works". But AppLocale is a lousy workaround...
Indeed, I would prefer going straight to Unicode/UTF-8 as well. Make it selectable on a per-window basis and we won't have problems during the transition period, when a lot of people still use country-specific encodings in for example European channels.
And seriously, implementing Unicode at a basic level is not as hard as people on this board have presented it to be. I don't think any of mIRC's core would need changing if the strings were kept as they are (UTF-8 encoded), and simply accept Unicode input (converting it to UTF-8 and continuing like normally) and decode the incoming text from UTF-8 (to UCS-2, which Windows uses) and render it as Unicode. Windows already supports Unicode just fine. Difficulty is no excuse in this case, and I know what I'm talking about. :-)
