Microsoft has finally released the much anticipated version 4.0 of the Enterprise Library.  Two of the biggest changes in this release are support for Visual Studio 2008 and the integration of the Unity dependency injection container, also dubbed the Unity Application Block.  You can download the new version from Microsoft Download Center, free of charge!

If you are a developer and are unfamiliar with the enterprise library, head over to the Enterprise Library home page and check it out.  Here is an excerpt from their site:

The patterns & practices Enterprise Library is a collection of reusable software components (application blocks) designed to assist software developers with common enterprise development challenges (such as logging, validation, data access, exception handling, and many others). Application blocks are a type of guidance; they are provided as source code plus documentation that can be used "as is," extended, or modified by developers to use on complex, enterprise-level line-of-business development projects.