tl;dr: Logo is an interpreted Lisp dialect designed for learning, emphasizing interactivity, descriptive error messages, and modular procedure-based programming where user-defined words behave identically to built-in primitives. It uses dynamically-typed words and lists (numbers are just special words), supports recursion, and is best known for turtle graphics. Enhanced variants include Object Logo, MicroWorlds (multi-tasking), and StarLogo (massively parallel).