In the beginning, you had only Dexterity to create customizations. A few years later, VBA was embedded into the product, providing access to a stress-free cross-dictionary functionality. After that, Continuum entered the scene for Visual Basic and Delphi programmers. Continuum provided even more access to third-party dictionaries and was an efficient tool for smaller-scale customizations.
In Version 7 of Dexterity, COM objects were supported. Now you could integrate web services with Dynamics GP and call them. Using COM, Continuum was repurposed as an Application Programming Interface (API) for Dynamics GP objects.
Then, Visual Studio Tools (VS Tools) came along. VS Tools opened the black box that was the Dynamics dictionary, and the ability to customize Dynamics GP spread like a virus. Suddenly, there was a long list of options for you to choose from for custom development.
On the home front, tools were being acquired that were targeted at power users instead of programmers...