GNU LESSER GENERAL PUBLIC LICENSE
Version 2.1, February 1999
Copyright (C) 1991, 1999 Free Software Foundation, Inc.
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
Everyone is permitted to copy and distribute verbatim copies of this license document,
but changing it is not allowed.
[This is the first released version of the Lesser GPL. It also counts as the successor of
the GNU Library Public License, version 2, hence the version number 2.1.]
The licenses for most software are designed to take away your freedom to share and
change it. By contrast, the GNU General Public Licenses are intended to guarantee your
freedom to share and change free software--to make sure the software is free for all its
This license, the Lesser General Public License, applies to some specially designated
software packages--typically libraries--of the Free Software Foundation and other
authors who decide to use it. You can use it too, but we suggest you first think carefully
about whether this license or the ordinary General Public License is the better strategy
to use in any particular case, based on the explanations below.
When we speak of free software, we are referring to freedom of use, 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 this service if you wish); that you
receive source code or can get it if you want it; that you can change the software and
use pieces of it in new free programs; and that you are informed that you can do these
To protect your rights, we need to make restrictions that forbid distributors to deny
you these rights or to ask you to surrender these rights. These restrictions translate to
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For example, if you distribute copies of the library, whether gratis or for a fee, you must
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We protect your rights with a two-step method: (1) we copyright the library, and (2) we
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To protect each distributor, we want to make it very clear that there is no warranty for the
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should know that what they have is not the original version, so that the original author`s
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Finally, software patents pose a constant threat to the existence of any free program.
We wish to make sure that a company cannot effectively restrict the users of a free
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any patent license obtained for a version of the library must be consistent with the full
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