http://interactiveasp.net/blogs/natesstuff/archive/2011/06/28/code-duel-to-learn-more-about-pex-and-code-contracts.aspxHere is a fun little C# Duel: http://pexforfun.com/Default.aspx (click Random Puzzle) I solved my first one in just 1 try (compilations) so it doesn’t take long to try. What is Pex and how does it work? http://pexforfun.com/Documentation.aspx#HowDoesPexWorkenCommunityServer 2008 (Build: 30417.1769)