blob: 128a6ccbcb8ea6115dfd63348172c297b83ce43a [file] [log] [blame]
<chapter id="chapter-licensing">
<title>Licensing advisory</title>
<sect1 id="section-application-licensing">
<title>How to license the applications you build with <application>GStreamer</application></title>
The licensing of GStreamer is no different from a lot of other libraries
out there like GTK+ or glibc: we use the LGPL. What complicates things
with regards to GStreamer is its plugin-based design and the heavily
patented and proprietary nature of many multimedia codecs. While patents
on software are currently only allowed in a small minority of world
countries (the US and Australia being the most important of those), the
problem is that due to the central place the US hold in the world economy
and the computing industry, software patents are hard to ignore wherever
you are.
Due to this situation, many companies, including major GNU/Linux
distributions, get trapped in a situation where they either get bad
reviews due to lacking out-of-the-box media playback capabilities (and
attempts to educate the reviewers have met with little success so far), or
go against their own - and the free software movement's - wish to avoid
proprietary software. Due to competitive pressure, most choose to add some
support. Doing that through pure free software solutions would have them
risk heavy litigation and punishment from patent owners. So when the
decision is made to include support for patented codecs, it leaves them
the choice of either using special proprietary applications, or try to
integrate the support for these codecs through proprietary plugins into
the multimedia infrastructure provided by GStreamer. Faced with one of
these two evils the GStreamer community of course prefer the second option.
The problem which arises is that most free software and open source
applications developed use the GPL as their license. While this is
generally a good thing, it creates a dilemma for people who want to put
together a distribution. The dilemma they face is that if they include
proprietary plugins in GStreamer to support patented formats in a way that
is legal for them, they do risk running afoul of the GPL license of the
applications. We have gotten some conflicting reports from lawyers on
whether this is actually a problem, but the official stance of the FSF is
that it is a problem. We view the FSF as an authority on this matter, so
we are inclined to follow their interpretation of the GPL license.
So what does this mean for you as an application developer? Well, it means
you have to make an active decision on whether you want your application
to be used together with proprietary plugins or not. What you decide here
will also influence the chances of commercial distributions and Unix
vendors shipping your application. The GStreamer community suggest you
license your software using a license that will allow proprietary plugins
to be bundled with GStreamer and your applications, in order to make sure
that as many vendors as possible go with GStreamer instead of less free
solutions. This in turn we hope and think will let GStreamer be a vehicle
for wider use of free formats like the formats.
If you do decide that you want to allow for non-free plugins to be used
with your application you have a variety of choices. One of the simplest
is using licenses like LGPL, MPL or BSD for your application instead of
the GPL. Or you can add an exception clause to your GPL license stating
that you except GStreamer plugins from the obligations of the GPL.
A good example of such a GPL exception clause would be, using the
Totem video player project as an example:
The authors of the Totem video player project hereby grants permission
for non-GPL-compatible GStreamer plugins to be used and distributed
together with GStreamer and Totem. This permission goes above and beyond
the permissions granted by the GPL license Totem is covered by.
Our suggestion among these choices is to use the LGPL license, as it is
what resembles the GPL most and it makes it a good licensing fit with the
major GNU/Linux desktop projects like GNOME and KDE. It also allows you to
share code more openly with projects that have compatible licenses.
Obviously, pure GPL code without the above-mentioned clause is not usable
in your application as such. By choosing the LGPL, there is no need for an
exception clause and thus code can be shared more freely.
I have above outlined the practical reasons for why the GStreamer
community suggests you allow non-free plugins to be used with your
applications. We feel that in the multimedia arena, the free software
community is still not strong enough to set the agenda and that blocking
non-free plugins to be used in our infrastructure hurts us more than it
hurts the patent owners and their ilk.
This view is not shared by everyone. The Free Software Foundation urges
you to use an unmodified GPL for your applications, so as to push back
against the temptation to use non-free plug-ins. They say that since not
everyone else has the strength to reject them because they are unethical,
they ask your help to give them a legal reason to do so.
This advisory is part of a bigger advisory with a FAQ which you can find
on the <ulink url="">GStreamer website</ulink>