SmartIrc4net is a multi-threaded and thread-safe IRC library written in C#. It allows you to communicate with IRC servers. The API features full channel syncing and is split in 3 layers: IrcConnection, IrcCommands and IrcClient.
A easy to use, easy to implent, IRC library with DCC (Download) support for C#.
See for more information:
https://github.com/EldinZenderink/SimpleIRCLib
Twitch C# library for accessing Twitch chat and whispers with events, Twitch API with both authenticated and unauthenticated calls, and PubSub with events.