This package was retrieved from and was repackaged to .tar.gz. Everything but the src/ tree and readme.txt was removed, since demo.dat in particular was not free. You are free to distribute this software under the terms of the GNU General Public License, version 2. On Debian systems, the complete text of the GNU General Public License can be found in the file `/usr/share/common-licenses/GPL-2'. Note that only the demo engine is under the GPL -- the demo data (which resides in the package amoeba-data) is not.