Extension Developers: Please migrate your extension to use ResourceLoader for front-end resources as soon as possible. While extensions that do not use ResourceLoader should continue to work in MediaWiki 1.17, there may be some side-effects (read the migration guide to learn how to fix them or migrate to ResourceLoader entirely).
About ResourceLoader 
- → See ResourceLoader/Features for a complete walk through of ResourceLoader
ResourceLoader solves this problem by loading resources on-demand and only for browsers that can run them. Although there is much more to it, the overal flow for client-side performance can be summarized by these 3 points:
- Minifying and concatenating
→ which reduces the code's size and parsing/download time
- Batch loading
→ which reduces the number of requests made
- Data URI embedding
→ which further reduces the number of requests, response time and bandwidth
Optionally images referenced in stylesheets can be embedded as data URIs. Together with the gzipping of the server response, those embedded images, together, function as a "super sprite".
- Features – Complete overview of ResourceLoader features.
- Developing with ResourceLoader – notes on configuring your development environment and on switching ResourceLoader between development and production modes.
- Migration guide for extension developers – a guide to making extensions to work with ResourceLoader.
- Migration guide (users)
- Default modules – an overview of all default modules and their methods, supported with documentation and examples.
- Vocabulary – the vocabulary used in ResourceLoader (such as Loader, Module, Requirement, etc.)
- Requirements – requirements gathered from a variety of sources during the planning stage.
Project documents 
- Version 1 Design Specification – the design specifications developed and maintained throughout the development process.
- Version 2 Design Specification – the design specifications begin developed for the next version.
Todo and tasks 
- Tasks - Random uncategorized todo list
- Task management (V1) – tracking bug for V1
- Task management (V2) – tracking bug for V2
|Documentation||Features · Vocabulary · Migration guide (users) · Migration guide (developers) · Developing with ResourceLoader · Default modules|
|Project information||Status updates · Version 1 Design Specification (tasks) · Version 2 Design Specification (tasks / tests) · Requirements|