It looks that on system 10.4 Tiger or 10.5 Panther one must install only: 1. XCode Tools (from installation DVD of MacOS X) 2. MacTeX - http://www.tug.org/mactex/ 3. Survex – http://www.survex.com and therion: Download the therion source, expand it by doubleclick and copy the therion folder to Application folder. Than from terminal: 0. cd /Application/therion 1. make config macosx 2. make 3. sudo make install All other bits are installed in system yet or in XCode Tools. There is a bug in therion if you install therion on new installed MacOS X system the folder /usr/local/etc is not created. The installation script of therion doesn't mkdir etc, so one must to do it manually. Only remaining problem is with VTK and with Loch. m.