I really don't get the lispm's answer about cl21. What are the hidden treasures of the genuine Common Lisp we are ignorant of?<p>In my humble opinion Common Lisp is the classic example of the kitchen sink syndrome, where many pieces taken from various dialects were put together in a hurry. The results is not that bad (like, say, C++) but we know, arguably, a much more refined versions of Lisp, such as the dialect from Symbolics and Arc.<p>So, honestly, what are these hidden gems?<p>cl21, it seems, was an attempt to unify some syntactic forms rather than re-define what a Common Lisp is or should be. In that respect it is very remarkable effort. It is also a package - don't use if don't like.<p>The fair point that Common Lisp is a truly multi-paradigm language, so it includes mutating primitives alongside with "pure" functions and supports lexical and dynamic scooping, is rather difficult to grasp, but there is a lot of possibilities at the level of syntactic forms and embedded specialized DSLs, which, arguably, is what makes a Lisp Lisp.<p>It is never too much of embedded DSLs and syntactic sugar.