I'm having a problem with an app-server behind a firewall. When it tries to compile my JSP code, it goes looking for this DTD: http://java.sun.com/dtd/web-jsptaglibrary_1_2.dtd However, as my app-server can't get out through the firewall it can't load this DTD and therefore it cannot compile the page. I could modify the XML to point at a local copy of the DTD, but this isn't very portable. Is there some generic mechanism for mapping DTD resources to local files? (In case this can only be done using proprietary mechanisms, I happen to be using WebSphere.) Thanks.