It allows Office applications to host the .NET Framework Common Language Runtime (CLR), enabling extensions written in C# or Visual Basic.
It is crucial to distinguish between the and the Development Tools . vsto 2010 runtime
This is a complete technical report regarding the . It allows Office applications to host the
Microsoft ended Extended Support for the VSTO 2010 Runtime on July 14, 2020 . vsto 2010 runtime
VSTO 2010 uses a COM Shim (generated by the runtime) to act as a proxy between the unmanaged Office application and managed .NET code. This prevents version conflicts and allows multiple add-ins to coexist.