. Microsoft enterprise data application blocks is an excellent data access layer component which can be used to reduce the coding effort for database applications significantly. Its a free download from MSDN The goals of Enterprise Library are the following: Consistency . All Enterprise Library application blocks feature consistent design patterns and implementation approaches. Extensibility . All application blocks include defined extensibility points that allow developers to customize the behavior of the application blocks by adding their own code. Ease of use . Enterprise Library offers numerous usability improvements, including a graphical configuration tool, a simpler installation procedure, and clearer and more complete documentation and samples. Integration . Enterprise Library application blocks are designed to work well together or individually. Links to download various versions of Microsoft enterprise library For .Net framework 3.5 - http://msdn.microsoft.com/en-us/library/d...