Note this blog is obsolete, see for the current blog Ever wondered how you would use a composite component within a composite component? Or is it not possible? It most certainly is possible, so lets see how! First we define level 2 (the deepest nesting) <?xml version='1.0' encoding='UTF-8' ?> <!DOCTYPE html> <html xmlns=""       xmlns:h=""       xmlns:cc="">     <head>         <title></title>     </head>     <body>         <cc:interface></cc:interface>         <cc:implementation>             This is coming from a nested composite component! Hurray :)         </cc:implementation>     </body> </html> Then we define level 1 (as you normally would, but now you will use a composite component within this composite component) <!DOCTYPE html> <html xmlns=""       xmlns:cc=""       xmlns:mypanel="">     <head>         <title></title>     </head>     <body>         <cc:interface></cc:interface>         <cc:implementation>             <mypanel:mypanel/>         </cc:implementation>     </body> </html> And then the page where we use the nested composite component <!DOCTYPE html> <html xmlns=""       xmlns:h=""       xmlns:mypanel="">     <h:head>         <title>Composite component</title>     </h:head>     <h:body>         <h2>Composite component</h2>         <mypanel:nested/>     </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 it. Enjoy!