Vector

Vector is the default skin for MediaWiki.

History
Created in 2009 as part of the work done by the Wikipedia Usability Initiative, Vector became the default skin for MediaWiki wikis in 2010, succeeding MonoBook. Several years ago, the skin underwent a number of changes, such as the switch to Mustache and the addition of new features. The latter are controllable by feature switches so that users can still be served the legacy layout. In 2022, as part of MediaWiki 1.38, Vector got a huge update, and the old Vector skin is now called Legacy Vector.

Basic

 * Reduced clutter, primarily by reducing the number of lines on screen
 * More prominent placement of the search portal
 * Visual separation of the content-action and namespace links, the former of which being divided into view tabs and action menu items
 * Automatic increase/decrease of margins throughout the user interface based on browser size
 * Use of a star icon for watch and unwatch actions

Vector Extension

 * Simplified search portal, including suggestions
 * Collapsible navigation portals
 * Alert when leaving an edit page without saving
 * Automatic hiding of tabs that do not fit on screen

Experimental Features

 * Simplified footer content
 * Search box expands on focus
 * Section edit links are moved to be directly next to heading instead of on the right, and they use an icon

Other Features

 * CollapsibleNav support via CollapsibleVector extension