Public Rights Licences
The FreeCard License
Like many programs that are created by individuals cooperating via the internet and other indirect means, certain legal issues have to be clarified before the start to ensure everyone agrees to the ways in which their intellectual property, be it images, source code or other supplies, will be used and usable by others. To this and, we have devised the FreeCard license, which is basically the GNU General Public License with a special exception tagged on to allow for the needs of the specific targeted group of users we are aiming at with FreeCard.
We chose the GPL as our main license since we want FreeCard to remain available free of charge for every user, and to encourage source code sharing. However, we also wanted to ascertain users wishing to create commercial software using FreeCard can do so without having to put up with what many people call the "GPL Virus", which is a clause in the GPL that says every program linked with code under the GPL must be placed under the GPL, too. This clause comes into play whenever a user creates a standalone stack, which is basically the stack merged with its own copy of the FreeCard program.
To work around this problem, every source file to be submitted to the FreeCard developers must include a special exception that gives users further rights and leverages the requirement to distribute the sources along with the program:
It allows placing stacks with FreeCard merged into them under any licence,
given this licence doesn't permit extracting FreeCard from
this combination in
ways the GPL would not allow
You are not required to ship the sources along; rather, you just have to tell the users that they can get the source code and where they can get it. If you did not make any modifications to the FreeCard program, this usually means you can just give them a link to the FreeCard web site where you obtained your copy of FreeCard from and make sure your link is still current from time to time.
The FreeCard exception from the GPL
If you intend to contribute to FreeCard, you have to place your contribution either under the GNU General Public License (GPL) or the GNU Lesser General Public License (LGPL). The best way to do this is to add the following notice to your contribution's readme file or add it as a comment to the start of any source code files you may be submitting:
<your contribution> is (c) Copyright <year> by <your name>. It is free software; you can distribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.
As a special exception, you may publish an integrated combination of FreeCard in executable form together with your data to be displayed using FreeCard, under your choice of license, provided that (1) the license does not permit extraction of the FreeCard executable from the combination other than in accord with the terms of the GNU General Public License, that (2) you state prominently either in or with the combination the precise location where the complete corresponding source code for the same version of FreeCard is openly available on a widely used network, and where you can reasonably expect it to remain available for at least one year after you first publish the combination.
<your contribution> is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with <your contribution>; if not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
You wil also want to add information on how to contact you by electronic and paper mail. There are also some more things you might want to consider, which you can find in the section on applying the GPL to your new programs. Note that it documents how to use the GPL without the special exception required for FreeCard source code.