Konversation is a fully-featured IRC client for Linux.
Ranked in these QuestionsQuestion Ranking
Pro Regularly maintained
Konversation is still being updated with new features and bug fixes. Konversation 1.5(released January 15, 2014) has added plenty of major features.
Konversation has an OSD(On Screen Display) feature that gives you an overlay message anytime your nick is mentioned. This means you won't be interrupted from your work and reduces the need to keep the window open.
Pro Plenty of useful smaller features
Koversation is full of features to make IRC simpler and smoother. It comes with tools like a channel bookmarker, the ability to insert special characters easily and the "URL catcher", which gives quick access to any links mentioned in the channel.
Pro Quick Buttons
The Quick Buttons features allows you to set a button to any IRC command that you frequently use. It has several defaults such as whois, and kick but a button can be created for any command you need.