Extending Visual Studio Application Lifecycle Management
You can customize some aspects of Visual Studio to extend existing features or to add new capabilities if you have special requirements. For example, you might define new test conditions for database unit tests if the test conditions provided with Visual Studio Premium or Visual Studio Ultimate are insufficient to address your requirements.
Some of the extensibility points are provided with your Visual Studio installation. For other extensibility points, you must also install the Visual Studio SDK. You can identify the specific requirements for each extensibility point in the content that supports that extensibility point.