The Managed Extensibility Framework is getting closer and closer to RTM. In this regard, developers taking advantage of the latest releases of Microsoft's development platform and tools now have available a fresh preview of the Managed Extensibility Framework. Designed to work in conjunction with Visual Studio 2010 and .NET Framework 4, the Managed Extensibility Framework Preview 6 comes with support for the latest iteration of the Redmond company's alternative to Adobe Flash, namely Silverlight 3, which was released to web the past week.

“In the three months that have passed since the last release, we’ve been very busy making final adjustments to get closer to RTM. I’ve summarized the biggest changes between the Preview 5 and Preview 6 releases. The highlights are: Silverlight support; Lazy<T> replaces Export<T>; Collection import changes; Inheritance changes; Export attribute is unsealed; Stable Composition makes its debut,” revealed Nicholas Blumhardt, Microsoft program manager.

The Managed Extensibility Framework is offered as a new library for .NET Framework 4. Developers can leverage MEF in order to build extensible applications while enjoying a streamlined maintenance process. It is important to note that Preview 6 of the Managed Extensibility Framework is the feature-complete library designed to kick up a notch the level of reuse of applications and components. Microsoft plans to include MEF version 1.0 in the final version of .NET Framework 4.

“Using MEF, .NET applications can make the shift from being statically compiled to dynamically composed. If you are building extensible applications, extensible frameworks and application extensions, then MEF is for you,” reads an excerpt of the framework's description on CodePlex. “MEF is in development. The source available on this site, does not reflect the final state of the product, it is a preview of what will be shipping in the framework in the future.”

Managed Extensibility Framework Preview 6 is available for download here.