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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 prob-
lems 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, alt-
hough 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 de-
velopment 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 Genera
l 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” o
f 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 secondari
ly
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 in-
teraction 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 rec
ognized standards body,
or, in the case of interfaces specified for a particular programming language, one that is widely used among developers
working in that language.
The “System Libraries” of an executable work include anything, other than the work as
a whole, that (a) is included in
the normal form of packaging a Major Component, but which is not part of that Major Component, and (b) serves only
to enable use of the work with that Major Component, or to implement a Standard Interface for which an implemen-
tation is available to the public in source code form. A “Major Component”, in this context, means a major essential
