Sample of web.xml

<web-app version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"> 

    <!-- //// -->    
    <!-- ZK -->    
    <listener>    
        <description>ZK listener for cleanup when a session is destroyed</description>        
        <listener-class>org.zkoss.zk.ui.http.HttpSessionListener</listener-class>        
    </listener>    
    <servlet>    
        <description>ZK loader for evaluating ZUML pages</description>        
        <servlet-name>zkLoader</servlet-name>        
        <servlet-class>org.zkoss.zk.ui.http.DHtmlLayoutServlet</servlet-class>        

        <!-- Must. Specifies URI of the update engine (DHtmlUpdateServlet).        
        It must be the same as <url-pattern> for the update engine.        
        -->        
        <init-param>        
            <param-name>update-uri</param-name>            
            <param-value>/zkau</param-value>            
        </init-param>        
        <load-on-startup>1</load-on-startup><!-- MUST -->        
    </servlet>    
    <servlet-mapping>    
        <servlet-name>zkLoader</servlet-name>        
        <url-pattern>*.zul</url-pattern>        
    </servlet-mapping>    
    <servlet-mapping>    
        <servlet-name>zkLoader</servlet-name>        
        <url-pattern>*.zhtml</url-pattern>        
    </servlet-mapping>    
    <servlet>    
        <description>The asynchronous update engine for ZK</description>        
        <servlet-name>auEngine</servlet-name>        
        <servlet-class>org.zkoss.zk.au.http.DHtmlUpdateServlet</servlet-class>        
    </servlet>    
    <servlet-mapping>    
        <servlet-name>auEngine</servlet-name>        
        <url-pattern>/zkau/*</url-pattern>        
    </servlet-mapping>    
    <!-- //// -->    

    <!-- MIME mapping -->    
    <mime-mapping>    
        <extension>gif</extension>        
        <mime-type>image/gif</mime-type>        
    </mime-mapping>    
    <mime-mapping>    
        <extension>html</extension>        
        <mime-type>text/html</mime-type>        
    </mime-mapping>    
    <mime-mapping>    
        <extension>htm</extension>        
        <mime-type>text/html</mime-type>        
    </mime-mapping>    
                            <mime-mapping><extension>jad</extension><mime-type>text/vnd.sun.j2me.app-descriptor</mime-type></mime-mapping><mime-mapping>                            
        <extension>jpeg</extension>        
        <mime-type>image/jpeg</mime-type>        
    </mime-mapping>    
    <mime-mapping>    
        <extension>jpg</extension>        
        <mime-type>image/jpeg</mime-type>        
    </mime-mapping>    
    <mime-mapping>    
        <extension>js</extension>        
        <mime-type>application/x-javascript</mime-type>        
    </mime-mapping>    
    <mime-mapping>    
        <extension>png</extension>        
        <mime-type>image/png</mime-type>        
    </mime-mapping>    
    <mime-mapping>    
        <extension>txt</extension>        
        <mime-type>text/plain</mime-type>        
    </mime-mapping>    
    <mime-mapping>    
        <extension>xml</extension>        
        <mime-type>text/xml</mime-type>        
    </mime-mapping>    
    <mime-mapping>    
        <extension>zhtml</extension>        
        <mime-type>text/html</mime-type>        
    </mime-mapping>    
    <mime-mapping>    
        <extension>zul</extension>        
        <mime-type>text/html</mime-type>        
    </mime-mapping>    

    <welcome-file-list>    
        <welcome-file>index.zul</welcome-file>        
        <welcome-file>index.zhtml</welcome-file>        
        <welcome-file>index.html</welcome-file>        
        <welcome-file>index.htm</welcome-file>        
    </welcome-file-list>    
</web-app>