Quantifying the need for custom tools

This is a Treemap of the classes in Glamorous Toolkit grouped into packages. The blue rectangles denote classes that have custom Inspector views. The green rectangles denote classes that define Examples.

Essentially, the whole system is touched by custom views that are then complemented by examples. These were created out of engineering needs (as opposed to marketing needs). What does this mean? It shows that Moldable Development addresses a pervasive need and it is relevant at any level of abstraction.