Linux

Circe, because why would you ever want to leave Emacs

Irssi

irssi or hexchat (earlier xchat) since forever. I’m one of the weird people that even paid for xchat on Windows ages ago.

I’ve never liked the clients that were just an extension in something else, like Pidgin.

Hexchat and Weechat are both great. Konversation if you use KDE fits nicely with the DE. But, I only use IRC about an hour per month.

I don't use IRC much, but Polari was good I think.

I've also been using irssi, which has been good

Only tried issri on CLI Linux… Hexchat on windows I couldn’t eve get to connect lol. What are people using to keep IRC open, so you can look back on chats? Pretty new to it

For Emacs users one of the Emacs-based clients is often the best choice for the simple reason that you have access to all the usual Emacs cozies. It's just another buffer. My pick is rcirc but they all work well enough, it comes down to personal preferences. Besides IRC I use it for all of my chat-type activity through bitlbee and other gateways. Over the decades chat protocols have come and gone but thanks to my IRC based setup they are all the same to me and all from the comfort of my Emacs session.

I'm curious what keeps you on IRC and stops you migrating to Matrix?

Hexchat is best chat. Also, are you trying to start a war?

Try HexChat 😉.

I'm using both, irssi and quassel.

I use hexchat in combination with znc

I use The Lounge, it's a self hosted server/bouncer that you use through a web UI. That makes it so I can stay online 24/7, and can access IRC from any device including my phone. It even supports push notifications, so when someone pings me on IRC, I get notified on my phone and can go open up the client and look at my chats. It's pretty good!

Not as lightweight as a terminal client, but keeping a Firefox tab open for it isn't that memory hungry. Negligible when you have dozens of tabs open and a few Electron apps anyway.