Office projects require NETFX 3.5

Sun, August 19, 2007, 09:25 PM under Orcas
If you try to use VSTO v3 in Visual Studio 2008, you'll notice that the project templates are only available when you select .NET Framework v3.5 (via the multitrgeting feature). You'll probably ask yourself "why?".

The answer becomes obvious when you realise that the MAF (part of Fx 3.5) is actually an evolution of the add-in infrastructure used by the Visual Studio Tools for Office team. They worked on this initially and in the 3rd iteration handed it to the CLR team so it could be baked for public use, not just private use by the Office add-ins. So, now they still depend on it of course which is why the VSTO redist depends on Fx 3.5. They also took further dependencies on some of the new security bits in System.Core, WindowsBase in Fx 3.0 for the packaging APIs and some other less major things. Now you know ;-)