DotNetMQ is a message broker (message queue, message oriented middleware) that has several features including guaranteed delivering, routing, load balancing, server graphs... so on. See article on CodeProject.com for more information: http://www.code
FireIRC is an IRC Client that brings the ideas of mIRC, X-Chat, and Linkinus all into one client. With FireIRC you get lots of extendability for whatever needs you need on IRC.
High performance C++ UDP-based networking library on UDT, suitable for games or VoIP applications