Does MEF require .NET 4?

Question

I am using Visual Studio 2010, try to create a MEF application. Does this require .NET 4.0 or can I target .NET 2.0?

Answer 1

Yes you do:

Application requirements change frequently and software is constantly evolving. As a result, such applications often become monolithic making it difficult to add new functionality. The Managed Extensibility Framework (MEF) is a new library in .NET Framework 4.0 that addresses this problem by simplifying the design of extensible applications and components.

From: http://mef.codeplex.com/

Edit: The question about targeting .net 2.0 is answered here:

http://mef.codeplex.com/Thread/View.aspx?ThreadId=54008

MEF is not supported on .NET 2.0 as it depends on LINQ and Expression trees. Currently we do not have a .NET 2.0 version of MEF planned.

Answer 2

Strictly speaking you don't have to have .Net 4.0 installed. You can use MEF with .Net 3.5 - if you reference System.ComponentModel.Composition.dll.

As DannyLane says, however, you do need the LINQ functionality so you can't target .Net 2.0.