VSTO - Office Interop API Extensions

Available in .NET Framework 3.5.
These are a set of additional interop assemblies that can be referenced to make working with COM Interop easier.
These are installed as part of the [[VSTO Power Tools]].
The Office Interop API Extensions are libraries that make working with optional parameters, variant types and parameterized properties easier when writing C# VSTO..

VSTO - C# Method Overloads

Eliminates the use of System.Type.Missing
Eliminates the use of Variant

VSTO - C# Optional Parameters

Creates a single argument class that contains all the necessary parameters.
Provides you with an equivalent to optional parameters
This functionality was added in Visual Studio 2010.
For more details, refer to [[Optional Parameters]]

VSTO - C# Parameteried Properties

Uses extension methods to remove the _get and _set methods.
This functionality was added in Visual Studio 2010.