The new Unity Dependency Injection Container available as stand-alone or within Enterprise Library 4.0 uses ObjectBuilder 2.0. ObjectBuilder 2.0 was started by Brad Wilson and Scott Densmore for use as the Dependency Injection Container for CodePlex. ObjectBuilder 2.0 will now be used as the shiny, new engine for both Enterprise Library 4.0 and Unity.
Chris Tavaras has made some heavy tweeks to ObjectBuilder 2.0 as part of the Enterprise Library 4.0 and Unity Projects, too, so it will be exciting to see just how much better our experiences will be with the lightweight Unity Dependency Injection Container on top of ObjectBuilder 2.0.
From a marketing standpoint, I think developers already using Castle Windsor, SpringFramework, and StructureMap will probably not move to Unity just because it sits on top of ObjectBuilder no matter what the version and how much better it is than the previous versions. I could be wrong and only time will tell, of course. Not that this is important :)
Since I use Enterprise Library quite a bit in my projects, this is a huge value-add to me as now I will have a dependency injection container as part of Enterprise Library 4.0 as well as believe it will be much easier to use and configure the application blocks as well as hook into them by using the extensibility mechanism in Unity.
Did I mention I asked for a Dependency Injection Container in the Enterprise Library survey done by Grigori? Now you know why...