Start off using HexChat for a client. You can find channels here: https://netsplit.de/channels/. Source: about 1 year ago

First off, grab yourself an IRC client. On their connection info page Hackint has information for both WeeChat and Hexchat, but you could use any IRC client. Source: over 1 year ago

Gajim is for XMPP. For IRC you need Hexchat or Weechat or something like that. Source: over 1 year ago

Hexchat is one of the more popular ones. Source: over 1 year ago

IRC - Also still around and in some cases, the same as it ever was, albeit with a smaller user base. A list of networks can be found here, and while there are many actively developed IRC clients out there, if you don't know where to start, most people recommend HexChat. Reddit's affiliated network is called Snoonet. mIRC is still actively developed by Khaled Mardam-Bey, so by all means, feel free to give that a... Source: over 2 years ago

Just came across CoyIM. Looks promising, it's basically XMPP + Tor + OTR. It even has interoperability with other OTR and XMPP clients. Source: over 2 years ago

I believe most apps have removed OTR support due to usability issues. However, https://coy.im/ still has it and has a Windows version, but I've never used it. Also Pidgin has terrible XMPP support, but does still have a separate OTR plugin and can run on Windows. Source: about 3 years ago