Recently I was asked: “Where can I find the API documentation on MSDN for plugins for enhancing the debugger?”

Good question. There are quite a few ways to extend Visual Studio, so it can be a bit overwhelming. I can think of four levels of extensibility off the top of my head right now; I'll list them from least involved to most involved:

  1. Macros - to check them out, go to View->Other Windows->Macro Explorer. The samples in the VSDebugger node will help you get started. These are best used for automating simple, repetitive tasks.
  2. Visualizers - Dissatisfied with the display of a managed type in the debugger? Create a visualizer for it. These aren't currently available in VS 2003 - see my previous post on how to create one for the PDC build of Whidbey.
  3. Add-ins - File->New Project, and find the Visual Studio .NET Add-in project template under Extensibility Projects. With an Add-in you can add commands to Visual Studio's menus which do anything you want, like computing your project's KLOC or creating a new user interface for some VS feature.
  4. VSIP (Visual Studio Industry Partner) Program - This is where things get serious. This program provides detailed information about VS to allow you to mold VS to your will. VSIPs have gone so far as to create completely new debugging engines for Visual Studio.

Hopefully that helps aspiring VS extenders everywhere. :0) Need more information on the spectrum of VS extensibility?