Link: Enterprise Library 4.0 download on MSDN

Enterprise Library 4.0 – May 2008 has been released and can be downloaded from the following link (in addition to it's CodePlex home ofcourse): http://www.microsoft.com/downloads/details.aspx?familyid=90de37e0-7b42-4044-99be-f8ecfbbc5b65&displaylang=en&tm