had yet to port the newer JRE over to Mac OS X. The Java–JavaScript functionality supported by the redesigned Java Runtime Environment is still called "LiveConnect", despite the Open Java Interface-specific approach having been abandoned. With Netscape 4, NPAPI was extended to allow plugins to be scripted. This extension is called LiveConnect. A plugin could implement a Java class and expose an instance of it. The class could be called from JavaScript and from Java applets running within the page. The disadvantage of LiveConnect is, that it is heavily tied to the version of Java embedded within the Netscape browser. This prevented the browser from using other Java runtimes, and added bloat to the browser download size, since it required Java to script plugins. Additionally, LiveConnect is tricky to program: The developer has to define a Java class for the plugin, run it through a specialized Java header compiler, and implement native methods. Handling strings, exceptions, and other Java objects from C++ is non-obvious. In addition, LiveConnect uses an earlier and now obsolete application programming interface (API) for invoking native C++ calls from Java, called JRI. The JRI technology has long since been supplanted by JNI. XPConnect XPConnect (Cross Platform Connect) is a technology which enables simple interoperation between XPCOM and JavaScript. Object connection XPConnect allows JavaScript objects to transparently access and manipulate XPCOM objects. It also enables JavaScript objects to present XPCOM compliant interfaces to be called by XPCOM objects. A main goal is that objects communicating from either side of an XPCOM style interface should not generally need to know or care about the implementation language of the object on the other side of the interface. XPConnect's primary reason for existence is to replace handwritten code used in places where native code needs to interact with JavaScript code. An example is the DOM module. Security Full privileges are only granted by default to chrome scripts, i.e. scripts that are part of the application or of an extension. For remote HTML/XHTML/XUL documents, most XPCOM objects are not accessible by the scripts as they have limited privileges due to security reasons. Even if they are accessible (e.g. the XMLHttpRequest object), the usual security restrictions can also be found (e.g. cannot open URLs of other domains). Mozilla was already using XPCOM to define the interfaces to many objects implemented in C++. Each interface was defined by an IDL file, and run