http://blogs.msdn.com/b/zxue/archive/2010/04/21/microsoft-enterprise-library-5-0-released.aspxMicrosoft Enterprise Library is a collection of application blocks designed to assist developers with common enterprise development challenges. Application blocks are a type of guidance, provided as source code that can be used "as is," extendeden-USTelligent Evolution Platform Developer Build (Build: 5.6.50428.7875)