JSTL 1.0 Beta 2, an implementation of the JSTL Proposed Final Draft specification, is available. JSTL encapsulates, as simple tags, core functionality common to many JSP applications. For example, instead of suggesting that you iterate over lists using a scriptlet or different iteration tags from numerous vendors, JSTL defines a standard tag that works the same everywhere. This standardization lets you learn a single tag and use it on multiple JSP containers. Also, when tags are standard, containers can recognize them and optimize their implementations.
JSTL has support for common, structural tasks such as iteration and conditionals, tags for manipulating XML documents, internationalization tags, and SQL tags. It also introduces the concept of an expression language to simplify page development, and includes an preliminary version of the JSP
expression language.