If folks are looking for an easy introduction to working with
ResourceLoader, one way might be to help with bug 26306 "Cleanup extensions
that include jquery (and common plugins) themselves":
https://bugzilla.wikimedia.org/show_bug.cgi?id=26306
A number of extensions over the years have pulled in their own copies of
jQuery, or particular jQuery or jQuery.ui plugins which are now present in
MediaWiki core and available through ResourceLoader.
The extra copies -- which are usually horribly out of date! -- can generally
now be removed.
Here are commits I made on a couple extensions:
OpenID: needed conversion to RL, used the opportunity to clean up other
minification/spriting
http://www.mediawiki.org/wiki/Special:Code/MediaWiki/87845
Collection: most of the old modules had already been switched to RL but the
old files were still there. Cleaned up and swapped one more plugin for the
core copy
http://www.mediawiki.org/wiki/Special:Code/MediaWiki/87847
Don't be afraid to check out
http://www.mediawiki.org/wiki/ResourceLoader/Migration_guide_for_extension_…
related doc pages on
mediawiki.org, or bug your fellows -- anything that's not clear now is
something that should be documented better, so don't be shy!
-- brion