CLiki (unfortunately not a WikiName, but nevertheless too good a naming opportunity to pass up What, was CeeLiki? taken?) is a Wiki-like application written in CommonLisp. You can find it at http://www.cliki.net/ , where it's hosting a bunch of pointers to free CL resources around the net.
CLiki is freely available (MIT-style licence) from your nearest vn-cclan node: see http://ww.telent.net/cclan/
Someone asks ``BTW, any free CL for MacOsx?'': Yes: choose from GNU CLISP (http://clisp.sf.net/) or OpenMCL (http://openmcl.clozure.com), or (after August 2003) SBCL. OpenMCL is probably the preferred choice for most people.
Common Lisp Wiki