Users Guide

course, the commands you use may be called something other than `show w' and `show c'; they could even be mouse-clicks or
menu items--whatever suits your program. You should also get your employer (if you work as a programmer) or your school, if
any, to sign a "copyright disclaimer" for the program, if necessary. Here is a sample; alter the names: Yoyodyne, Inc., hereby
disclaims all copyright interest in the program `Gnomovision' (which makes passes at compilers) written by James Hacker.
signature of Ty Coon, 1 April 1989 Ty Coon, President of Vice This General Public License does not permit incorporating your
program into proprietary programs. If your program is a subroutine library, you may consider it more useful to permit linking
proprietary applications with the library. If this is what you want to do, use the GNU Lesser General Public License instead of
this License.
GNU GENERAL PUBLIC LICENSE
Version 3, 29 June 2007 Copyright © 2007 Free Software Foundation, Inc. Everyone is permitted to copy and distribute
verbatim copies of this license document, but changing it is not allowed.
Preamble
The GNU General Public License is a free, copyleft license for software and other kinds of works. The licenses for most
software and other practical works are designed to take away your freedom to share and change the works. By contrast, the
GNU General Public License is intended to guarantee your freedom to share and change all versions of a program--to make sure
it remains free software for all its users. We, the Free Software Foundation, use the GNU General Public License for most of our
software; it applies also to any other work released this way by its authors. You can apply it to your programs, too. 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
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.
Third party licenses
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