We use a software (a forum) written in PHP run on a single webserver. We modified the original software itself and applied software around it, e.g. using parts of the origin code in our own code. The whole package can only run as one thing.
Every file of the origin software has the following header:
* Simple Machines Forum (SMF)
* @package SMF
* @author Simple Machines http://www.simplemachines.org
* @copyright 2011 Simple Machines
* @license http://www.simplemachines.org/about/smf/license.php BSD
* @version 2.0.1
Following the license-link brings us to:
Copyright © 2011 Simple Machines. All rights reserved.
Developed by: Simple Machines Forum Project Simple Machines http://www.simplemachines.org
Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
- Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimers.
- Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimers in the documentation and/or other materials provided with the distribution.
- Neither the names of Simple Machines Forum, Simple Machines, nor the names of its contributors may be used to endorse or promote products derived from this Software without specific prior written permission.
We want to allow others to work with us on the code. We could use a closed repository as in the past and that would be fine. Nevertheless, to remove any hesitations to help us, we would publish the code as open source on GitHub, so everyone can contribute, who is willing to help.
Which license should have our own code? Usually I prefer MIT but I don't see, that it's possible to merge both codes. And are we able to publish the code to invite others to help to work on our very own special version of SMF? Especially, the third point in the license let me think, that's not possible.