Note this blog is obsolete, see for the current blog When you developed a composite component the namespace you would be seeing would look like "". But what if you are not allowed to use it that way or you just do not like it, is it possible to change that? Yes it is possible. This blog entry shows you how. The composite component <?xml version='1.0' encoding='UTF-8' ?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" ""> <html xmlns=""       xmlns:cc="">     <body>         <cc:interface></cc:interface>         <cc:implementation>             This is coming from a composite component with its own custom namespace! Hurray :)         </cc:implementation>     </body> </html> The .taglib.xml file <?xml version="1.0" encoding="UTF-8"?> <facelet-taglib xmlns=""                 xmlns:xsi=""                 xsi:schemaLocation=""                 version="2.0">     <namespace></namespace>     <composite-library-name>mypanel</composite-library-name> </facelet-taglib> And the web.xml <?xml version="1.0" encoding="UTF-8"?> <web-app version="3.0" xmlns=""          xmlns:xsi=""          xsi:schemaLocation="">     <context-param>         <param-name>javax.faces.PROJECT_STAGE</param-name>         <param-value>Development</param-value>     </context-param>     <context-param>         <param-name>javax.faces.FACELETS_LIBRARIES</param-name>         <param-value>/WEB-INF/mypanel.taglib.xml</param-value>     </context-param>     <servlet>         <servlet-name>Faces Servlet</servlet-name>         <servlet-class>javax.faces.webapp.FacesServlet</servlet-class>         <load-on-startup>1</load-on-startup>     </servlet>     <servlet-mapping>         <servlet-name>Faces Servlet</servlet-name>         <url-pattern>/faces/*</url-pattern>     </servlet-mapping>     <session-config>         <session-timeout>30</session-timeout>     </session-config>     <welcome-file-list>         <welcome-file>faces/index.xhtml</welcome-file>     </welcome-file-list> </web-app> And now lets use it! <!DOCTYPE html> <html xmlns=""       xmlns:h=""       xmlns:mypanel="">     <h:head>         <title>Composite component</title>     </h:head>     <h:body>         <h2>Composite component</h2>         <mypanel:mypanel/>     </h:body> </html> Note the code for this sample is available as part of the Glassfish samples (see the subversion repository at And that is. Enjoy!