It means somehow compatible with the Lisp 1.5 implementtion. Which is an interpreter/compiler, and a base library. It's the first widely used Lisp implementatio

It means somehow compatible with the Lisp 1.5 implementtion. Which is an interpreter/compiler, and a base library. It's the first widely used Lisp implementation. This implies cons cell based lists, s-expressions, and a whole bunch of basic control structures and facilities. The first Scheme dialects were quite similar to that, but deviated and extended this in their own direction with a series of language standards RNRS. If a langage is a Scheme dialect, call it Scheme. Basic rule: use the nearest (!) language name, one is compatible with. This strives to be a R7RS Scheme. Thus name it Schwme. Then the Scheme literature and the Scheme source libraries apply. If it is a Scheme, I would best get myself a Scheme tutorial to learn using it - reading the Lisp literature is of less direct help. For example typically Common Lisp implementations have 'Common Lisp' or 'CL' its name, and are not called SchemeSomething. SBCL, CCL, GCl, Allegro Cl, MCL, ECL, ... Exceptions are CLISP or the product LispWorks. To avoid confusion a language should call itself Lisp, when it is practically (syntactically) a Lisp, not just in the unspecified family of 'Lisp': Logo, Scheme, Clojure, MDL, Dylan, SKILL, ...