If you're interested in Forth, check out the online Thinking Forth book project: http://thinking-forth.sourceforge.net/ With the author's permission, several people collectively scanned and re-typeset the book because they didn't want it to stay out of print. (Quite a complement, for any author!)
TF is a really eloquent distillation of what Forth has taught the author about keeping programs maintainable, well-organized, and concise. Most of its techniques (often called "factoring") are applicable in almost any language, and it often reads like a predecessor to Martin Fowler's _Refactoring_. (The ideas spread from the Forth community to Smalltalkers over the fifteen years between the two.)
TF is a really eloquent distillation of what Forth has taught the author about keeping programs maintainable, well-organized, and concise. Most of its techniques (often called "factoring") are applicable in almost any language, and it often reads like a predecessor to Martin Fowler's _Refactoring_. (The ideas spread from the Forth community to Smalltalkers over the fifteen years between the two.)