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
NLog is a logging platform for .NET with rich log routing and management capabilities. It uses familar logger pattern known from log4xxx. Advanced routing options include buffering, asynchronous logging, load balancing, failover, and more.