User Guide

143
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.