It's a HTML version of the SICP textbook. This version replaces the Scheme code of the original with Lisp Flavored Erlang code.
While it's a tutorial for Lisp (LFE in this case), the book itself was a first year CS textbook intended to teach you how to think about programming in general.
While it's a tutorial for Lisp (LFE in this case), the book itself was a first year CS textbook intended to teach you how to think about programming in general.