<?xml version="1.0" encoding="UTF-8"?>
<chapter id="sid-5833084">
   <title>Introduction</title>
   <section id="sid-5833083">
      <title>What is it?</title>
      <para>Errai is a GWT-based framework for building rich web applications using next-generation web technologies. Built on-top of ErraiBus, the framework provides a unified federation and RPC infrastructure with true, uniform, asynchronous messaging across the client and server.</para>
   </section>
   <section id="sid-5833091">
      <title>Required software</title>
      <para>Errai requires a JDK version 6 or higher and depends on Apache Maven to build and run the examples, and for leveraging the quickstart utilities.</para>
      <itemizedlist>
         <listitem>
            <para>
            JDK 6.0:
            <ulink url="http://java.sun.com/javase/downloads/index.jsp"/>
            </para>
         </listitem>
         <listitem>
            <para>
            Apache Maven:
            <ulink url="http://maven.apache.org/download.html"/>
            </para>
         </listitem>
      </itemizedlist>
      <note>
         <title>Launching maven the first time</title>
         <para>Please note, that when launching maven the first time on your machine, it will fetch all dependencies from a central repository. This may take a while, because it includes downloading large binaries like GWT SDK. However, subsequent builds are not required to go through this step and will be much faster.</para>
      </note>
   </section>
</chapter>
