Obsolete
This feature is obsolete. Although it may still work in some browsers, its use is discouraged since it could be removed at any time. Try to avoid using it.

The documentation listed below is archived, obsolete material about open Web topics.

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Should not the "Browser compatibility" table also list Google Chrome and Konqueror? Chome is not mentioned at all, but is becoming increasingly popular. Konqueror is listed below the table, which seems inconsistent. Znerd 04 August 2009
Browser Detection and Cross Browser Support
Improper browser detection can lead to web maintenance nightmares. Rethinking the basics of when and how to detect user agents is crucial to creating maintainable, cross browser web content. This article reviews several approaches to browser detection, their usefulness in specific circumstances to arrive at a common sense approach to browser detection.
Browser Feature Detection
Summary: An experimental approach to discovering degree of support for Standards
Displaying notifications (deprecated)
Firefox offers support for "desktop notifications"; these are notifications that are displayed to the user outside the context of the web content, using the standard notification system provided by the operating system.
E4X
ECMAScript for XML (E4X) is a programming language extension that adds native XML support to JavaScript. It does this by providing access to the XML document in a form that feels natural for ECMAScript programmers. The goal is to provide an alternative, simpler syntax for accessing XML documents than via DOM interfaces. A valid alternative to E4X is a non-native JXON algorithm.
E4X Tutorial
This tutorial walks you through the basic syntax of E4X (ECMAScript for XML). With E4X, programmers can manipulate an XML document with a syntax more familiar to JavaScript programming.
forEach
Ok, in the end I didn't remove the old code as it isn't hosted anywhere (I thought the github reference contained the code) but inserted a faster implementation above while retaining the rest of the document.
Iterator
The Iterator function returns an object which implements legacy iterator protocol and iterates over enumerable properties of an object.
LiveConnect
(Please update or remove as needed.)
MSX Emulator (jsMSX)
Old Proxy API
Proxies are objects for which the programmer has to define the semantics in JavaScript. The default object semantics are implemented in the JavaScript engine, often written in lower-level languages like C++. Proxies let the programmer define most of the behavior of an object in JavaScript. They are said to provide a meta-programming API.
ParallelArray
The goal of ParallelArray was to enable data-parallelism in web applications. The higher-order functions available on ParallelArray attempted to execute in parallel, though they may fall back to sequential execution if necessary. To ensure that your code executes in parallel, it is suggested that the functions should be limited to the parallelizable subset of JS that Firefox supports.
Properly Using CSS and JavaScript in XHTML Documents
XHTML™ 1.0 The Extensible HyperText Markup Language (Second Edition) defines XHTML to be a reformulation of HTML 4 as an XML 1.0 application.
Reference
The guide section links to an interesting document discussing how to create and use private variables in objects, which is great if you want to protect the various properties within an object from being poked at accidentally. I also just read a document on proper inheritance using apply(). Well if you combine the two, you can have inherited private variables:
Scope Cheatsheet
JavaScript with Mozilla extensions has both function-scoped vars and block-scoped lets. Along with hoisting and dynamic behavior, scope in JavaScript is sometimes surprising.
Server-Side JavaScript
Here's a radical idea: Use one language to write entire Web apps -- the same language which billions of web pages already use, every day.
Sharp variables in JavaScript
A sharp variable is a syntax in object initializers that allows serialization of objects that have cyclic references or multiple references to the same object.
Standards-Compliant Authoring Tools
Creating cross-browser code upfront will save you lots of time quality testing your web content. The following authoring tools adhere to the W3 standards. If you're using older versions of tools that rely on old browser bugs or generate browser-specific code, it may be time to upgrade:
StopIteration
The StopIteration object was used to tell the end of the iteration in the legacy iterator protocol. Do not use this ancient feature.
Styling the Amazing Netscape Fish Cam Page
Using JavaScript Generators in Firefox
Generators can be used to simplify asynchronous code in Firefox by opting in to using JavaScript version 1.7 or later. You can opt in in HTML as follows:
Window.importDialog()
Because opening windows on mobile isn't necessarily appropriate, the Firefox Mobile team designed the importDialog() method to replace window.openDialog(). Instead of opening a new window, it merges the specified XUL dialog into the main window.
Writing JavaScript for XHTML
Technical review completed. Editorial review completed.
XForms
XForms were envisioned as the future of online forms as envisioned by the W3C. Drawing on other W3C standards like XML Schema, XPath, and XML Events, XForms tried to address some of the limitations of the current HTML forms model. However, XForms never gained traction and is now considered obsolete.

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