From the wonderful RedGuides Wiki

This widget allows you to embed a Cornify button into your wiki page.

It was created by Jeroen De Dauw.

Using this widget

For information on how to use this widget, see widget description page on MediaWikiWidgets.org.

Copy to your site

To use this widget on your site, just install MediaWiki Widgets extension and copy the full source code of this page to your wiki as page Widget:Cornify.