Visual diffs/zh

视觉差异（visual diff）比较和显示渲染（或显示）文档之间的差异，而不是出格式化的文档文本（或标记）. There are several "visual diff" efforts in the MediaWiki world:


 * The most visible one is a visual diffs system inside the visual editor, comparing the HTML of two documents (released in March 2017; pictured); eventually, this will be available on MediaWiki history and diff pages too.
 * As part of their testing efforts, the Parsing team created the "Visual Diff Testing" tool (released around April 2016), which is a pixel differ of the page rendered as an image, used to identify differences between Parsoid and the legacy parser.
 * Extension:On-Article Diff Highlighting (2011)
 * As part of Google Summer of Code 2008, guyvdb mentored by Brion created an HTML diffing tool in MediaWiki core, which was later removed in 2009.