The book excerpt is an exclusive sample chapter of the Book "Chapter 8: Building Simple Widgets", which gives a introduction to basic GUI building.
The linked article also contains an in depth interview with the books author, Lyle Johnson. The interview touches on topics such as
- how FXRuby is tied to the underlying native FOX toolkit
- how FXRuby deals with keeping GUIs responsive in light of Ruby 1.8.x userspace threads
- what makes FXRuby very compelling to use
- and more