Portable Perl-compatible regular expressions for Common Lisp

 CL-PPCRE is a portable regular expression library for Common Lisp
 which has the following features:
 .
  * It is compatible with Perl.
  * It is pretty fast.
  * It is portable between ANSI-compliant Common Lisp implementations.
  * It is thread-safe.
  * In addition to specifying regular expressions as strings like in Perl you
    can also use S-expressions.