After listening to a DotNetRocks podcast that interviewed Kevin McNeish on DSLs and Software Factories, I was curious to check out the DSL toolkit for internal use by our developers. After installing the Visual Studio 2008 SDK, I started seeing a “VSIP License Required” in the Visual Studio 2005 splash screen, and “A VSIP license is required to use this version of Microsoft Visual Studio” in the about box of Visual Studio 2005. However, within Visual Studio 2008’s about box I see “Visual Studio SDK License”. I was confused and wondered exactly when a VSIP license is required. I contacted someone at Microsoft and received clarification on this.
The Microsoft person verified that it is not necessary to join the VSIP program in order to build and use your own DSL implementation, internally or externally. Apparently when Visual Studio 2005 was first released, extending Visual Studio was only allowed by licensed partners, but this restriction was later lifted, and licenses aren't necessary anymore. Unfortunately the messages in the splash screen and about box were not updated. Good to know.