Optional packages are the new name for what used to be known as standard extensions .
This document describes the Java platform's mechanism for handling optional packages . An optional package is a group of packages housed in one or more JAR files that implement an API that extends the Java platform. An implementation of an optional package may consist of code written in the Java programming language and, less commonly, platform-specific native code. In addition, it may include properties, localization catalogs, images, serialized data, and other resources specific to the optional package. Support for optional packages in browsers such as Internet Explorer and Netscape Navigator is available through the Java Plug-in.