mIRC is an Internet Relay Chat (IRC) client that allows users to communicate in real-time with other people over the internet. It is often used for group conversations, but it can also be used for one-on-one conversations. The app is designed to be easy to use and intuitive, with a graphical user interface that allows users to quickly join a chatroom and start chatting. mIRC supports a wide range of commands and features, including the ability to create and manage channels, private messages, file transfers, and user authentication. It also includes a scripting language that allows users to automate certain tasks and customize the interface. mIRC is one of the most popular IRC clients, and it is available for free on Windows, macOS, and Linux.
Discontinued empathy is not currently maintained. The latest version, 3.25, released in August 2017, can still be downloaded from the official website.
It's free, has some nice additional features and a better scripting language.
Good features, very stable and free, apart from mIRC, there is nothing better out there.
Discontinued The program is no longer updated. The latest version, 2.8.8, released in May 2010, can still be downloaded from the official website.
It is clearly an IRC application. Just because it can be self-hosted doesn't change that.
Suspended Shout development stopped in early 2016 and was replaced by its official community fork: http://alternativeapp.info/software/the-lounge/. See https://github.com/erming/shout
Open source, lightweight and customizable, I recommend it.