I think this is a great example of a book for learning a language. The cartoon illustrations are both funny and illustrative. The characters are consistent, too - each one represents a different concept.
Most people probably won't be using Forth in the future, but you can definitely learn about teaching a programming language from this book. Jt is a great example.
I love this book, but many people seem to dislike the cartoons. It reminds me of Learn You a Haskell, it's very hit and miss. So would I recommend this for a textbook? No. But as a book that people are offered of their own accord, yes definitely. The cartoons worked for me and I learned everything I could get out of the book.
Most people probably won't be using Forth in the future, but you can definitely learn about teaching a programming language from this book. Jt is a great example.