There are various bits of JavaScript in [[ https://en.wikipedia.org/wiki/MediaWiki:Common.js | Common.js ]] and default gadgets to customise the enwiki experience. It is a shame they are not customisable in LocalSettings.php or bits of code in the JS experience.
Let's aim to start removing the need for this code in enwiki (and then long term in other projects) and help update our software to meet the use cases/address the gaps that editors of that page have clearly identified.
Currently, the default gadgets (which registered users can opt-out) are these:
* [[ https://en.wikipedia.org/wiki/MediaWiki:Gadget-charinsert.js | MediaWiki:Gadget-charinsert.js ]], a loader for [[ https://en.wikipedia.org/wiki/MediaWiki:Gadget-charinsert-core.js | the script]] which makes the content of [[ https://en.wikipedia.org/wiki/MediaWiki:Edittools | Edittools]] clickable (on edit, preview and upload). This has many different forks on other wikis.
* [[ https://en.wikipedia.org/wiki/MediaWiki:Gadget-DRN-wizard-loader.js | MediaWiki:Gadget-DRN-wizard-loader.js ]], another loader, for [[ https://en.wikipedia.org/wiki/MediaWiki:Gadget-DRN-wizard.js | code ]] used only in the page [[ https://en.wikipedia.org/wiki/Wikipedia:Dispute_resolution_noticeboard/request | WP:Dispute resolution noticeboard/request]]
* [[ https://en.wikipedia.org/wiki/MediaWiki:Gadget-featured-articles-links.js | MediaWiki:Gadget-featured-articles-links.js]], used by a few wikis to add icons to the sidebar links to featured/good articles in other languages
* [[ https://en.wikipedia.org/wiki/MediaWiki:Gadget-mySandbox.js | MediaWiki:Gadget-mySandbox.js ]], which provide a link to the user's /sandbox subpage
* [[ https://en.wikipedia.org/wiki/MediaWiki:Gadget-ReferenceTooltips.js | MediaWiki:Gadget-ReferenceTooltips.js ]], used only on article, project, and help namespaces
* [[ https://en.wikipedia.org/wiki/MediaWiki:Gadget-refToolbar.js | MediaWiki:Gadget-refToolbar.js ]] the loader for the set of reference tools which is more appropriated to the current user's preferences (with respect to the edit toolbars and dialogs)
* [[ https://en.wikipedia.org/wiki/MediaWiki:Gadget-switcher.js | MediaWiki:Gadget-switcher.js ]] (new), use to "Show radio buttons to switch between views of certain content, such as some maps"
* [[ https://en.wikipedia.org/wiki/MediaWiki:Gadget-teahouse.js | MediaWiki:Gadget-teahouse.js ]], which is just a loader for [[https://en.wikipedia.org/wiki/MediaWiki:Gadget-teahouse/content.js | a script ]] which is used only in two pages.
* [[ https://en.wikipedia.org/wiki/Special:PrefixIndex/MediaWiki:Gadget-geonotice- | MediaWiki:Gadget-geonotice.js ]], another loader, for [[ https://en.wikipedia.org/wiki/MediaWiki:Gadget-geonotice-core.js | a script ]] which shows geo-localized messages to users (exclusively in their Watchlist)
Some of them were previously in Common.js, and some are just loaders for the main scripts which are used in specific pages. These would benefit from {T17075}.