This is a fork of Pascal Costanza’s Core Lisp, a hygiene-compatible Lisp dialect. It has been forked to work with Vernacular, an experimental module system for Common Lisp. It serves to show that Vernacular can, in fact, be used to build Racket-style language towers, despite Common Lisp’s lack of hygiene, “simply” by embedding a hygiene-compatible language within Common Lisp.

Core Lisp is an implementation of ISLISP, a standardized Lisp dialect “culturally compatible” with Common Lisp. That is, while it is not an exact subset of Common Lisp, it contains no features that make it unsuitable for implementation in Common Lisp.

Core Lisp provides a degree of hygiene equivalent to that provided by explicit renaming or syntactic closures. That’s a lot of hygiene, but not all the hygiene. You might want to read Towards the Essence of Hygiene, to understand where this approach falls short. (This approach being the one the author terms “binder renaming with gensym”.)