My new project is hopefully simple and straight forward: http://nunrar.codeplex.com/

This is a literal conversion of the JUnrar project by Edmund Wagner I started by using the Java Conversion Assistant 3.0 on JUnrar and have been cleaning up and fixing the code.  It works, minus volume support and probably other minor features.  

My goal is to make a fairly complete native Unrar library for general .NET use that anyone can use.  I believe the licensing allows free and unrestricted usage of unrar and junrar.

I hope it takes off.