This category covers extensions that allow editors to annotate texts or images. "Text annotation is the practice and the result of adding a note or gloss to a text, which may include highlights or underlining, comments, footnotes, tags, and links" (source: Wikipedia).

See also

• WikiApiary: Extension:AnnotationGenerator (used at Filtered Push); Extension:AnnotationLinks; Extension:AnnotatorReview
• Wikignome user script
• Google Summer of Code 2014: Annotation tool for Wikidata
• Extension:Cite for adding footnotes/endnotes