GlassFish Server supports tag libraries and standard portable tags. For more information, see the JavaServer Pages Standard Tag Library (JSTL) page at http://java.sun.com/products/jsp/jstl/index.jsp.
Web applications don’t need to bundle copies of the jsf-impl.jar or appserv-jstl.jar JSP tag libraries (in as-install/lib) to use JavaServerTM Faces technology or JSTL, respectively. These tag libraries are automatically available to all web applications.
However, the as-install/lib/appserv-tags.jar tag library for JSP caching is not automatically available to web applications. See JSP Caching, next.