NetIRC2 is an easy-to-use .NET IRC client library - a redone version of my original NetIRC. It supports all major features relevant to making a chat client or bot.
NetIRC2 has full support for synchronization contexts. You can use it from a Windows Forms or WPF GUI thread and chat events will be automatically dispatched, allowing you to completely ignore multithreading. It uses byte arrays internally so mixed encodings can be handled. The IrcClient class can even be used as a component in the Forms Designer.
Because it speeds up connect times with some IRC servers, an Ident server is included as well.
NetIRC2 uses the BSD license.