|GStreamer Plugin Writer's Guide (1.0.6)|
GStreamer is a plugin-based framework licensed under the LGPL. The reason for this choice in licensing is to ensure that everyone can use GStreamer to build applications using licenses of their choice.
To keep this policy viable, the GStreamer community has made a few licensing rules for code to be included in GStreamer's core or GStreamer's official modules, like our plugin packages. We require that all code going into our core package is LGPL. For the plugin code, we require the use of the LGPL for all plugins written from scratch or linking to external libraries. The only exception to this is when plugins contain older code under more liberal licenses (like the MPL or BSD). They can use those licenses instead and will still be considered for inclusion. We do not accept GPL code to be added to our plugins module, but we do accept LGPL-licensed plugins using an external GPL library. The reason for demanding plugins be licensed under the LGPL, even when using a GPL library, is that other developers might want to use the plugin code as a template for plugins linking to non-GPL libraries.
We also plan on splitting out the plugins using GPL libraries into a separate package eventually and implement a system which makes sure an application will not be able to access these plugins unless it uses some special code to do so. The point of this is not to block GPL-licensed plugins from being used and developed, but to make sure people are not unintentionally violating the GPL license of said plugins.
This advisory is part of a bigger advisory with a FAQ which you can find on the GStreamer website