JavaServer Pages is a Java Enterprise technology that enables web programmers to build pages using tags which access Java code running on the server. Custom JSP tag libraries, or taglibs, have been developed to enable developers to easily integrate different technologies into their JSP applications. The JSP Standard Tag Library, JSTL, is set to standardize the common features of many such libraries into a core set of tags of use to every JSP developer. The standard tag library provides tags for performing basic decision-making and repetition within a page, localization, handling XML data, and database access. It's also possible to extend the library with your own tags that collaborate with the standard tags. A core element of the library is its support for expression languages, which are used to share and access data between JSP pages. This book covers every aspect of the new JSTL specification, based on the reference implementation developed at the Apache Jakarta project. All the tags are explored, and real uses for the tag library demonstrated through the development of working web applications. This book bas been developed alongside the early access releases of the JSP standard tag library, and presents a practical overview of what the new tag library allows JSP developers to do.