RHYTHMBOX LICENSING



WHY WE USE THE GPL


Rhythmbox software is licensed to everyone under the GPL. The official name of the GPL is “GNU General Public License”, only the GPL license applies to the Rhythmbox software.


We use the GPL for Rhythmbox because it promotes software freedom. This document does not change the licensing of Rhythmbox in any way, it simply declares the interpretation of the GPL license on behalf of the licenser. This is important as under the law, only the common understanding of a licensor and his licensees matter.


THE GPL IS AN OPEN SOURCE LICENSE


The GPL allows you to do the following things with Rhythmbox software:


  1. Make unlimited copies of Rhythmbox software without payment of royalties or license fees.

  2. Distribute copies of Rhythmbox software.

  3. Make changes to Rhythmbox if you need to do so for use within your own company. The GPL license does not require you to share those internal changes with the rest of the community.

  4. Distribute changed versions of Rhythmbox to others, but if you distribute such changed versions you are required to share those changes with the rest of the community by publishing that changed source code under the GPL. This includes derivative works built on top of Rhythmbox.

WHY WE USE A RECIPROCAL LICENSE


Some open source licenses --- such as the BSD and Apache licenses --- do not contain this reciprocity obligation. While software distributed under those licenses is open source, modified versions of that software need not be open source. Companies or people can take such open source software and create proprietary versions. If we used such a non-reciprocal license for Rhythmbox, the risk would increase that our users would be faced with proprietary versions of Rhythmbox being distributed by different vendors, leading to important functionality not being returned to the community which spawned the original version. We do not believe this is appropriate for software into which many people have donated so much time and effort.


The objective of reciprocal open source licenses --- such as the GPL and LGPL licenses --- is to ensure that changes and improvements to open source software always remain available as open source software. Nobody will be able to convert Rhythmbox itself into proprietary software or to create incompatible versions with features that are available only to a few.


THE GPL AND LIBRARIES


The GPL uses some relatively unclear words in regards to how it affects other software. The licensor of Rhythmbox understanding of the GPL is that only derivative works as per copyright law are subject to the reciprocity obligation, mere aggregation do not cause the GPL to be invoked even if those mere aggregations are distributed in one unit (i.e. “as part of the whole”).


So in the opinion of the licenser of Rhythmbox, the software library frameworks which upon Rhythmbox is built, are not derivative works of Rhythmbox and as such the GPL's demands for reciprocity do not extend to them. So i.e. shipping Rhythmbox with GStreamer and its plugins is to be considered mere aggregation even if Rhythmbox is linked to GStreamer. There are some reciprocital obligations in the license of GStreamer, through its use of the LGPL license which of course affects the distribution of GStreamer, but that is a matter outside the scope of this document.


THE RHYTHMBOX GUARANTEE OF SOFTWARE FREEDOM


We intend for you to rely on this interpretation of the GPL. Regardless of what other misleading information you may hear about this license from others, this guarantees that Rhythmbox will be available for distribution for you without any risk to due to Rhythmbox linking to certain libraries which might or might not contain properietary software or open source software licensing in a GPL incompatible way.


The content of this document is approved by the Rhythmbox development team (in alphabetical order) represented by: