Do I Need to Use the Developer Studio Type Libraries to Create an Add-in?
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If you write the add-in in Visual Basic, you must use the Developer Studio type libraries to access the Developer Studio object model. These libraries contain definitions of all the objects, properties, methods, and events in the model.
Below are descriptions of the libraries and their locations on your computer:
Build system (Microsoft Visual Studio\Common\MSDEV98\Bin\Ide\Devbld.pkg)
Debugger (Microsoft Visual Studio\Common\MSDEV98\Bin\Ide\Devdbg.pkg)
Developer Studio shell (Microsoft Visual Studio\Common\MSDEV98\Bin\Devshl.dll)
Text editor (Microsoft Visual Studio\Common\MSDEV98\Bin\Devedit.pkg)
If you write the add-in in Visual C++, all you need are the header files provided with Visual C++. These files are in Microsoft Visual Studio\VC98\Include\ObjModel.