ResourceLoader

ResourceLoader is an optimizing JavaScript/CSS delivery system for MediaWiki, available in version 1.17 and later. Code that has not been explicitly integrated into ResourceLoader should still function, with some caveats; migration is highly recommended.

Documentation

 * /Documentation/Developing with ResourceLoader – notes on configuring your development environment and on switching ResourceLoader between development and production modes.
 * /Documentation/Using with extensions – a guide to making extensions to work with ResourceLoader.
 * /Default modules – an overview of all default modules and their methods, supported with documentation and examples.

Additional information on various topics is also available.
 * /Status – the status of the project.
 * /Design Specification – the design specifications developed and maintained throughout the development process.
 * /JavaScript Deprecations – JavaScript features that are planned to be replaced with modern equivalents.
 * /Requirements – requirements gathered from a variety of sources during the planning stage.

About ResourceLoader
On Wikimedia wikis, every page view includes hundreds of kilobytes of JavaScript. In many cases, some or all of this code goes unused due to browser support or because users do not make use of the features on the page. In these cases, bandwidth, and loading time spent on downloading, parsing and executing JavaScript code is wasted. This is especially true when users visit MediaWiki sites using older browsers like Internet Explorer 6, where almost all features are unsupported, and parsing and executing JavaScript is extremely slow.

ResourceLoader solves this problem by loading resources on demand and only for browsers can run them. It also improves client-side performance by:
 * minifying JavaScript and CSS code (which reduces the code's size and parsing time)
 * batch loading resources (which reduces the number of requests made)
 * optionally embedding images as data URIs (which can further reduce the number of requests made)

Todo

 * Test plan (in a Google document somewhere)
 * Documentation plan
 * Schedule (in a Google document somewhere)
 * Task management (Mostly in Google Docs. There is a tracking bug in Bugzilla)
 * Release management plan
 * Community management plan