[https://vuejs.org Vue.js] is a JavaScript framework that is [[mediawikiwiki:Vue.js|used in the MediaWiki project ]] (and just about everywhere else) for creating the frontend. For MediaWiki, Vue.js in used in the new [[mediawikiwiki:Codex|'''Codex''']] design system for Wikimedia. Codex replaces MediaWiki UI (and [[MediaWiki/Theming#OOUI - The Object Oriented User Interface|OOUI]]) which relied heavily on jQuery. While jQuery was great - and is still shipped<ref>https://www.mediawiki.org/wiki/ResourceLoader/Core_modules</ref> with MediaWiki core, the JavaScript and browser landscape has changed significantly leading to whole new JavaScript libraries and frameworks such as Vue.js.
https://gitlab.wikimedia.org/repos/design-systems/CodexExample is a repo that shows how to leverage Codex in your MediaWiki extensions.