<chapter id="introduction">
  <title>Introduction</title>

  <para>
    <emphasis>The Cal3D team welcomes you to the world of moving vertices!</emphasis>
  </para>

  <sect1>
    <title>What is Cal3D?</title>
    <para>
      Cal3D is a free skeletal-based 3d character animation library written
      in C++ in a platform/graphic-API independent way.
    </para>
    <para>
      Originally designed to be used in a 3d client for
      <ulink url="http://www.worldforge.org">WorldForge</ulink>, it evolved
      into a stand-alone library which can be used in many different kinds
      of projects.
    </para>
  </sect1>

  <sect1>
    <title>About this Guide</title>
    <para>
      This guide covers among other things
      <link linkend="decisions">Design Decisions</link>,
      <link linkend="installation">Installation</link>,
      <link linkend="compilation">Compilation</link>,
      <link linkend="architecture">Architecture</link> and
      <link linkend="usage">Usage</link>
      of the Cal3D library. A detailed description of the API is available
      in the separate &apiref;.
    </para>

    <formalpara>
      <title><xref linkend="introduction"></title>
      <para>
        This is the chapter you are currently reading. The most important part is
        the one about the <link linkend="licenses">Licenses</link>.
      </para>
    </formalpara>

    <formalpara>
      <title><xref linkend="decisions"></title>
      <para>
        This chapter provides some background information about the development of
        Cal3D. It does not contain any crucial facts you have to know in order to use
        the library, but it can help you understand why it was designed the way it is.
      </para>
    </formalpara>

    <formalpara>
      <title><xref linkend="setup"></title>
      <para>
        This chapter explains how you obtain, install and compile the Cal3D library.
      </para>
    </formalpara>

    <formalpara>
      <title><xref linkend="architecture"></title>
      <para>
        This chapter illustrates the architecture of the Cal3D library. All the components
        and terminologies are explained in every detail.
      </para>
    </formalpara>

    <formalpara>
      <title><xref linkend="usage"></title>
      <para>
        This chapter explains the usage of the Cal3D library step by step. The topics
        cover creation, modification, animation and rendering of models.
      </para>
    </formalpara>
  </sect1>

  <sect1>
    <title>Credits</title>
    <para>
      There are already numerous people who have made contributions in some sort to
      the Cal3D project. Here they are, in no specific order:
    </para>

    <para>
      Laurent Desmecht, Loic Dachary, Douglas Walsh, Nick Edgington, Marco Heidelberger, 
      Wolfgang Wester, Brandon Ehle, Igor Kravtchenko, Jeremy Moles,
      Wolfgang Scheicher, Stephan Stapel, Steve Cordon, Tomek Grudzinski and Ladislav Stefun.
    </para>

    <para>
      <emphasis>A very big thanks to all of you!</emphasis>
    </para>

    <para>
      <ulink url="https://mail.gna.org/listinfo/cal3d-devel/">The cal3d developers</ulink>
    </para>

  </sect1>

  <sect1 id="licenses">
    <title>Licenses</title>
    <para>
      The Cal3D User's Guide is licensed under the <link linkend="gfdl">GNU Free Documentation License (GFDL)</link>.
    </para>
    <para>
      The Cal3D library is licensed under the <link linkend="lgpl">GNU Lesser General Public License (LGPL)</link>.
      which among other things, allows you to link proprietary
      applications with it. The Cal3D team strongly believes in the <ulink url="http://www.fsf.org">Free Software</ulink>
      movement and provides this library without any additional restrictions.
      However, to make this a "fair deal" and to support the future development of
      the library, we invite you to follow these points when using the Cal3D library
      in your project:

      <orderedlist>
        <listitem>
          <para>
            Seriously consider releasing your project under a free license too.
          </para>
        </listitem>
        <listitem>
          <para>
            Read and understand the <link linkend="lgpl">LGPL</link> and make sure
            that your usage of Cal3D complies with it.
          </para>
        </listitem>
        <listitem>
          <para>
            Include a prominent mention about the usage of the Cal3D library in
            your project.
          </para>
        </listitem>
        <listitem>
          <para>
            Send a short message to us when you release your work.
          </para>
        </listitem>
        <listitem>
          <para>
            Provide feedback to the Cal3D project to help us enhance it.
          </para>
        </listitem>
      </orderedlist>
    </para>

    <para>
      Furthermore, here are a few other possibilities to help the Cal3D project:

      <orderedlist>
        <listitem>
          <para>
            We are always in need of models, animations, textures and demos. So,
            if you have something to spare, send it along!
          </para>
        </listitem>
        <listitem>
          <para>
            Sponsoring and donations can definitively help the project, just contact
            <ulink url="https://mail.gna.org/listinfo/cal3d-devel/">us</ulink>.
          </para>
        </listitem>
        <listitem>
          <para>
            Have you heard of a new animation technology? Is there a freshly written,
            earth-shaking paper about inverse-kinematics on your desk? Fell free to
            send such stuff to the Cal3D project, so we can put it into the library!
          </para>
        </listitem>
      </orderedlist>
    </para>

  </sect1>

</chapter>

