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LicensesPage

Licenses we use for the code

We use two licenses: GNU GPL (v. 2 or, at your option, any later version) and Affero GPL. The idea is to use Affero whenever possible, but fall to GPL with code that links/is derived from other code that uses the GPL 2. The GPL 2 is incompatible with Affero GPL (see the links above and below for discussion), but is likely to be upwards compatible with GPL v. 3.

Why the Affero GPL

We use the Affero GPL license because we specifically want to prevent anybody from grabbing the code, making changes/imporvements, and then running it on a web server without allowing us (or anybody else) to have access to that code. The Affero GPL is specifically designed to cover these cases, as explained in the Affero GPL FAQ, the GNU GPL FAQ and discussed by RMS recently.

A comparison/review of several licenses, including an explanation of why some licenses are incompatible with the GPL v. 2 and what that means is available from the GNU site .

What will happen when the GPL 3 comes out?

If the GPL v. 3 is compatible with the Affero GPL and/or explicitly covers/allows to cover the web server situation, we will then relicense all the code under the GPL v. 3. (Most of the code we cannot license under the Affero GPL is now licensed under "GPL version 2 or, at your option, any later version").

License for the documentation

All documentation, unless otherwise stated, is released using the Attribution-NonCommercial-ShareAlike v. 2.5 of the Creative Commons license .

Give credit where credit is due

Please, if you use this software for your analyses or in your own development, or use/modify the documentation, etc, give credit where credit is due. Notice that the copyright holders are not the same for all programs or documents. If in doubt, just ask.