MonoBook

MonoBook is a MediaWiki skin that was the previous default skin for Wikimedia Foundation websites.

History
MonoBook became the default skin in MediaWiki 1.3 as a replacement for the Standard skin. Later, it adopted support for responsive web design for narrow, mobile phone displays, which also is designed with progressive enhancement in mind to maximize compatibility. On May 13, 2010, Vector replaced MonoBook as the default skin. MonoBook is still present on many wikis using older versions of MediaWiki software.