We have been doing some more detailed looking into the licensing for Drupal. The problem is a complex one and the subject of quite a bit of speculation in the software world. It has yet to be definitively decided in the courts. Drupal is licensed under an open source license called the GNU Public License (GPL) version 2. Most open source CMS software of note is licensed under this same license (Joomla!, modX, Plone, etc.)
What this license essentially tries to guarantee is that once software is created it remains freely modifiable and freely distributed. It is a particular kind of license which also requires that any software that combines with software under this license also must be licensed with that license.
For you, our clients, that means that any work that Dayspring does that is “built on” Drupal must also be GPL. Additionally it means:
1. You can definitely give the software away to anybody without needing to pay Dayspring additional licensing fees.
2. Dayspring must provide you with source code so that you can modify it yourself.
3. It is also possible (subject to legal interpretation) that another organization could force you to make the code that Dayspring developed for you freely available. This does not, as far as I understand, include the look-and-feel of the site, graphics, etc. But it would include any custom modules that were developed—for example, for tracking user information.
Practically, it seems unlikely that someone would try to force you to freely distribute any software that we develop for you that is tied to Drupal. But if this is a problem for you, we would need to reconsider whether building on Drupal is the right route to take.
The text of the license is here http://www.gnu.org/licenses/gpl-2.0.html if you wish to review it yourself.
I realize that this is all very complicated. If you spend any time at all reading conversations among software developers, etc. about the subject, it’s enough to make your head spin.
