Surely you have heard of Enterprise Library: The bundled Microsoft application blocks redelivered in a set of reusable components to help development teams focus on business functionality instead of low level technical plumbing such as data access, logging, etc. Consistency, extensibility, ease of use and integration have been goals from the start and it is being improved in every release. If you are not using it on your current solution you probably have a good reason not to.

It is easy to start working with Enterprise Library since the download contains a lot:

1. Binaries, which you can use in your application, and the configuration editor, which enables you to configure settings for each application block in a graphical user interface.

2. Very useful documentation available through Visual Studio help containing background info on EntLib, how to get started, how to develop with EntLib, its design and detailed descriptions of each block.

3. Source that you can optionally install. If you do, you get source code of all (42) EntLib projects and quickstarts for each application block.

Before, you could get Entlib 3.1 to work with Visual Studio 2008, but that took some effort. Installing it and then making it appear in VS was not straightforward. Now the waiting is over:

Enterprise Library 4 can easily be used in Visual Studio 2008 and .NET Framework 3.5. http://msdn.microsoft.com/en-us/library/cc512464.aspx Also EntLib got better performance, WMI 2.0 support and a few minor fixes. But wait, that is not all.... The new kid in town is Unity Application Block!

Unity is a lightweight dependency injection container, which facilitates loosely coupled object development and creation and extensible caching. http://msdn.microsoft.com/nl-nl/library/cc468366(en-us).aspx It can be used standalone too in Visual Studio 2005 and 2008. The Stoplight and EventBroker quickstarts give a good overview of the possibilities of Unity. Once you get to know the Dependency Injection and Inversion of Control are very powerful patterns, nicely described here Inversion of Control Containers and the Dependency Injection pattern.