R6RS/R7RS Scheme system.

Features:

 -  Builtin CLOS.
 -  Common Lisp like reader macro.
 -  Cryptographic libraries.
 -  Customisable cipher and hash algorithm.
 -  Custom codec mechanism.
 -  CL like keyword lambda syntax (taken from Gauche).
 -  Constant definition form. (define-constant form).
 -  Builtin regular expression
      -  mostly works O(n)
 -   Replaceable reader

WWW: https://code.google.com/p/sagittarius-scheme/
