Strange Code

"[No Starch Press] had me at 'esolangs' . . . I am almost always a fan of a book that talks about how to build a programming language. This one not only talks about some of the concepts involved in doing that, and shows how to build two custom languages (Filska and Firefly), AND talks about a few popular esoteric languages and how they warp your brain in a good way, it takes the unusual step of examining some languages that Kneusel describes as 'atypical,' which have some interesting and useful properties. His coverage of CLIPS, alone, is worth the price of admission here. 

The knowledge gained here is foundational, and will help [you] with all sorts of different kinds of applications . . . I think every programmer should read it." 
—Ted Neward, "The Dude of Software," Principal, Neward & Associates; Technologist, Executive Leader, Speaker/Author

"A fascinating and thought-provoking tour through programming languages. Strange Code guides you through some mostly forgotten languages—such as Forth, SNOBOL, and CLIPS—before exploring more experimental languages—such as Piet—where your source code is an image. I particularly enjoyed Firefly, a language for the BBC micro:bit, created especially for the book."
—Sean McManus, Author of Mission Python: Code a Space Adventure Game!

"[Gives] a grounding in the basics of concepts like Turing Completeness without leaving readers to fend for themselves in a forest of of dense computer science arcana. As a reference and source for teachers, Strange Code has much to commend it."
—Terry Freedman, Teach Secondary magazine