Visual Studio 2008

With the past few releases of Visual Studio, each Visual Studio release only supported a specific version of the .NET Framework. For example, VS 2002 only worked with .NET 1.0, VS 2003 only worked with .NET 1.1, and VS 2005 only worked with .NET 2.0.

One of the big changes is starting with the VS 2008 release is to support what we call "Multi-Targeting" - which means that Visual Studio will now support targeting multiple versions of the .NET Framework, and developers will be able to start taking advantage of the new features Visual Studio provides without having to always upgrade their existing projects and deployed applications to use a new version of the .NET Framework library.

Now when you open an existing project or create a new one with VS 2008, you can pick which version of the .NET Framework to work with as shown above - and the IDE will update its compilers and feature-set to match this. Among other things, this means that features, controls, projects, item-templates, and assembly references that don't work with that version of the framework will be hidden, and when you build your application you'll be able to take the compiled output and copy it onto a machine that only has an older version of the .NET Framework installed, and you'll know that the application will work.