ET and its auxiliary programs are copyrighted, but may be used without restrictions and the package may be redistributed in its entirety provided that this copyright notice is attached. Incorporation of the whole ET package in compilations of software, including those for which a fee is charged, is permitted, provided that redistribution is allowed. Those parts of the package for which source code is provided are made available under the terms of the GPL (GNU General Public License). Unfortunately, this cannot be done for the ET editor itself, since I do not own copyright to some of the source code, and therefore I cannot distribute all of the source code.