These directories hold executable binary distributions of earlier versions of Icon. For the latest version of Icon under Unix (including Cygwin or Macintosh), get the current source code and build it. for more information, see: http://www.cs.arizona.edu/icon/ http://www.cs.arizona.edu/icon/uguide/macintosh.htm http://www.cs.arizona.edu/icon/uguide/cygwin.htm The windows directory holds binaries of the Windows distribution; see http://www.cs.arizona.edu/icon/v95w.htm