To use GoodProfOrNot you need these software packages first (freely available):
Optional:
GoodProfOrNot is distributed under the GNU General Public License.
There are no restrictions on usage: you are free to modify and use GoodProfOrNot and run it on your own web site, which is typically all you'll want to do. However, as a courtesy we ask you not to obscure or mis-represent the server software (e.g., do publicly link to http://goodprofornot.sf.net/)
If you wish to further redistribute, then you must accept the terms of the GPL: if you distribute binaries, distribute source under GPL. Since the code is in Python (normally an interpreted language), this is easy.
You can also visit the Development page for the most cutting-edge version.