One thing not mentioned is that Visual C++ and Visual Basic historically were separate IDEs with separate codebases. When the time came to unify them, only one of them could continue on. My understanding is that Visual Basic won, and that today's Visual Studio IDE (devenv.exe, msenv.dll, etc.) is the continuation of that VB codebase.
I don't actually know in which release that transition happened. But since there's a screenshot of each version in the article, presumably that transition is visually documented...