Microsoft announced the release of Enterprise library 5.0. Enterprise library is set of reusable software components which will help to accelerate the enterprise application development. This version of enterprise library is targeted to support .Net 4.0 version. You can download this at http://www.microsoft.com/downloads/details.aspx?FamilyId=bcb166f7-dd16-448b-a152-9845760d9b4c&displaylang=en Know more about Enterprise library 5.0 here