<sect1>

    <title>Preamble</title>

    <para>The licenses for most software are designed to take away

    your freedom to share and change it.  By contrast, the GNU General

    Public License is intended to guarantee your freedom to share and

    change free software–to make sure the software is free for

    all its users.  This General Public License applies to most of the

    Free Software Foundation's software and to any other program whose

    authors commit to using it.  (Some other Free Software Foundation

    software is covered by the GNU Library General Public License

    instead.)  You can apply it to your programs, too.</para>

    <para>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 this service 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.</para>

    <para>To protect your rights, we need to make restrictions that

    forbid anyone to deny you these rights or to ask you to surrender

    the rights.  These restrictions translate to certain

    responsibilities for you if you distribute copies of the software,

    or if you modify it.</para>

    <para>For example, if you distribute copies of such a program,

    whether gratis or for a fee, you must give the recipients all the

    rights that you have.  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.</para>

    <para>We protect your rights with two steps: (1) copyright the

    software, and (2) offer you this license which gives you legal

    permission to copy, distribute and/or modify the software.</para>

    <para>Also, for each author's protection and ours, we want to make

    certain that everyone understands that there is no warranty for

    this free software.  If the software is modified by someone else

    and passed on, we want its recipients to know that what they have

    is not the original, so that any problems introduced by others

    will not reflect on the original authors' reputations.</para>

    <para>Finally, any free program is threatened constantly by

    software patents.  We wish to avoid the danger that redistributors

    of a free program will individually obtain patent licenses, in

    effect making the program proprietary.  To prevent this, we have

    made it clear that any patent must be licensed for everyone's free

    use or not licensed at all.</para>

    <para>The precise terms and conditions for copying, distribution

    and modification follow.</para> 

</sect1>