ZyXEL Communications NSA-220 Plus User Manual page 385

Appendix E Open Source Licences
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.
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