Appendices
23
When we speak of free software, we are referring to freedom, not price. Our General Public Licenses are designed to make sure
that you have the freedom to distribute copies of free software (and charge for them if you wish), that you receive source code or
can get it if you want it, that you can change the software or use pieces of it in new free programs, and that you know you can do
these things.
To protect your rights, we need to prevent others from denying you these rights or asking you to surrender the rights. Therefore,
you have certain responsibilities if you distribute copies of the software, or if you modify it: responsibilities to respect the
freedom of others.
For example, if you distribute copies of such a program, whether gratis or for a fee, you must pass on to the recipients the same
freedoms that you received. You must make sure that they, too, receive or can get the source code. And you must show them
these terms so they know their rights.
Developers that use the GNU GPL protect your rights with two steps: (1) assert copyright on the software, and (2) offer you this
License giving you legal permission to copy, distribute and/or modify it.
For the developers' and authors' protection, the GPL clearly explains that there is no warranty for this free software. For both
users' and authors' sake, the GPL requires that modified versions be marked as changed, so that their problems will not be
attributed erroneously to authors of previous versions.
Some devices are designed to deny users access to install or run modified versions of the software inside them, although the
manufacturer can do so. This is fundamentally incompatible with the aim of protecting users' freedom to change the software.
The systematic pattern of such abuse occurs in the area of products for individuals to use, which is precisely where it is most
unacceptable. Therefore, we have designed this version of the GPL to prohibit the practice for those products. If such problems
arise substantially in other domains, we stand ready to extend this provision to those domains in future versions of the GPL, as
needed to protect the freedom of users.
Finally, every program is threatened constantly by software patents. States should not allow patents to restrict development and
use of software on general-purpose computers, but in those that do, we wish to avoid the special danger that patents applied to
a free program could make it effectively proprietary. To prevent this, the GPL assures that patents cannot be used to render the
program non-free.
The precise terms and conditions for copying, distribution and modification follow.
TERMS AND CONDITIONS
0. Definitions.
“This License” refers to version 3 of the GNU General Public License.
“Copyright” also means copyright-like laws that apply to other kinds of works, such as semiconductor masks.
“The Program” refers to any copyrightable work licensed under this License. Each licensee is addressed as “you”. “Licensees”
and “recipients” may be individuals or organizations.
To “modify” a work means to copy from or adapt all or part of the work in a fashion requiring copyright permission, other than the
making of an exact copy. The resulting work is called a “modified version” of the earlier work or a work “based on” the earlier
work.
A “covered work” means either the unmodified Program or a work based on the Program.
To “propagate” a work means to do anything with it that, without permission, would make you directly or secondarily liable for
infringement under applicable copyright law, except executing it on a computer or modifying a private copy. Propagation
includes copying, distribution (with or without modification), making available to the public, and in some countries other
activities as well.
To “convey” a work means any kind of propagation that enables other parties to make or receive copies. Mere interaction with a
user through a computer network, with no transfer of a copy, is not conveying.
An interactive user interface displays “Appropriate Legal Notices” to the extent that it includes a convenient and prominently
visible feature that (1) displays an appropriate copyright notice, and (2) tells the user that there is no warranty for the work
(except to the extent that warranties are provided), that licensees may convey the work under this License, and how to view a
copy of this License. If the interface presents a list of user commands or options, such as a menu, a prominent item in the list
meets this criterion.
1. Source Code.
The “source code” for a work means the preferred form of the work for making modifications to it. “Object code” means any non-
source form of a work.
A “Standard Interface” means an interface that either is an official standard defined by a recognized standards body, or, in the
