Properties may be defined within the <library>, <module>, <project>, and <resource> elements within an enclosing <properties> element. Library properties serve as the most generic and are inherited by processor and module definitions. Modules, projects and resources inherit property setting from their enclosing module.
The <type> and <include> elements may also contain <property> declarations as direct child elements.
| name | The property name. | 
| value | The property value. | 
Property values may contain references to system properties and properties defined within the enclosing property set (locally or inherited) using the form ${<name>}.
Example:
<property name="username" value="${user.name}"/>
      Example property definition from the DPML root module.
<module name="dpml" basedir="main">
  <properties>
    <property name="project.publisher.name" value="Digital Product Management Library"/>
    <property name="project.specification.vendor" value="${project.publisher.name}"/>
    <property name="project.implementation.vendor" value="${project.publisher.name}"/>
    <property name="project.implementation.vendor-id" value="net.dpml"/>
    <property name="project.publisher.url" value="http://www.dpml.net"/>
    <property name="project.resource.host" value="http://repository.dpml.net"/>
    <property name="project.api.host" value="http://api.dpml.net"/>
    <property name="project.svn.host" value="svn://svn.berlios.de/dpml/trunk/main"/>
  </properties>
  ...
</module>
Example property definition within a project type directive.
<module name="metro">
  ...
  <project name="dpml-metro-runtime" basedir="runtime">
    <types>
      <type id="jar"/>
      <type id="plugin">
        <property name="project.plugin.class" 
           value="net.dpml.metro.runtime.CompositionController"/>
      </type>
    </types>
    <dependencies>
      <include ref="dpml/util/dpml-logging-api" tag="public"/>
      <include ref="dpml/util/dpml-activity-api" tag="public"/>
      <include ref="dpml/util/dpml-parameters-impl"/>
      <include ref="dpml/util/dpml-configuration-impl"/>
      <include key="dpml-state-impl"/>
      <include key="dpml-metro-component" tag="protected"/>
      <include key="dpml-metro-model" tag="protected"/>
    </dependencies>
  </project>
  ...
</module>