1. opensymphony
  2. xwork

Source

xwork / src / test / com / opensymphony / xwork / config / providers / xwork-test-package-inheritance.xml

<!DOCTYPE xwork PUBLIC
    "-//OpenSymphony Group//XWork 1.1.1//EN"
    "http://www.opensymphony.com/xwork/xwork-1.1.1.dtd"
 >

<xwork>
    <package name="default" namespace="/default">
        <action name="default" class="com.opensymphony.xwork.ActionSupport"/>
    </package>

    <package name="abstractPackage" abstract="true">
        <action name="abstract" class="com.opensymphony.xwork.ActionSupport"/>
    </package>

    <package name="singleInheritance" namespace="/single" extends="default">
        <action name="single" class="com.opensymphony.xwork.ActionSupport"/>
    </package>

    <package name="multipleInheritance" namespace="/multiple" extends="default,abstractPackage,singleInheritance">
        <action name="multiple" class="com.opensymphony.xwork.ActionSupport"/>
    </package>
</xwork>