The author is not unwilling to explain, he has lots of experience trying to explain and knows how hard it can be.
The best single sentence description, IMHO, is that GT (Glamorous Toolkit) is the current manifestation, implementation, proof of concept of the idea that making systems explainable through mouldable development is very powerful.
Furthermore it is a very nice tool in its own right (again IMHO).
Saying 'GT is x' where x is any of the subjects in the text is problematic. Most people will cling to one perspective, the one they are most familiar with or like the most, and mostly forget the other ones.
Smalltalk is indeed so simple that all complexity moves to the implementation level. This is good, because it allows all users to explore how things work, given a learning curve.
Since a Smalltalk image normally contains all code for everything, it is its own best example.
There are many cool Smalltalk code bases, some of them already many years old, for example, Seaside (a web app framework) or Glorp (an object relational mapper).
Pharo (http://www.pharo.org), the currently most successful open source Smalltalk implementation, has many frameworks and libraries that can be loaded that are each good examples.
The best single sentence description, IMHO, is that GT (Glamorous Toolkit) is the current manifestation, implementation, proof of concept of the idea that making systems explainable through mouldable development is very powerful.
Furthermore it is a very nice tool in its own right (again IMHO).
Saying 'GT is x' where x is any of the subjects in the text is problematic. Most people will cling to one perspective, the one they are most familiar with or like the most, and mostly forget the other ones.
There is lots of stuff to read or watch:
- https://blog.feenk.com/ - https://book.gtoolkit.com
(BTW, everything you see in the above two web sites is actually written inside GT, notebook style with active content).
But reading about it is no substitute to trying it out and experiencing it yourself, though there is a learning curve for sure.