The software is copyrighted but not copy-protected. You may freely copy and distribute the program and the documentation as long as this is not done commercially. Please inform us (through the user support section of www.ecopath.org) when you copy the software to anyone, or if you received it from someone else. This will enable new users to be registered (free of charge), and thus to be informed of new developments, bugs, etc. At the same time, you are invited to send brief descriptions of your ecosystem models to the authors, initially for inclusion on ?http://www.ecopath.org/.