The Brodie books are both excellent. "Object Oriented Forth" by Dick Pountain is a succinct and practical exploration of applying Forth's metaprogramming capab

The Brodie books are both excellent. "Object Oriented Forth" by Dick Pountain is a succinct and practical exploration of applying Forth's metaprogramming capabilities to extend the language with various features. The best aspect of the book is that it works through many alternatives rather than taking a direct path. It's more about data structures and abstraction than OOP. Julian Noble (https://www.taygeta.com/fsl/docs/NobleArchive.html https://www.taygeta.com/fsl/docs/NobleArchive.html) also wrote a number of very interesting articles and books about Forth. There's an apparently ongoing project to re-typeset his "Scientific Forth": https://github.com/Josefg/Scientific_FORTH https://github.com/Josefg/Scientific_FORTH.