Simon Fraser demonstrated his MacTierra, which he developed from scratch in Object Pascal on the Macintosh, based on the description of Tierra in the Artificial Life II proceedings. Information on this program is available at:
http://www.santafe.edu/~smfr/mactierra.html
Fraser's MacTierra has a frontend which is far superior to the frontend of the official Tierra, including the new Beagle frontend. It includes all kinds of drag and drop and point and click capabilities. Together with Manor, they demonstrated how easily serious experiments with Tierra (Manor's subversion efforts) could be done while working in this environment.