VisualEditor provides a visual editor for wiki pages. It is written in JavaScript and runs in a web browser.
It uses the Parsoid parser to convert wikitext documents to annotated HTML which the VisualEditor is able to load, modify and emit back to Parsoid at which point it is converted back into wikitext.
For more information about these projects, check out the VisualEditor and Parsoid pages on mediawiki.
For information on installing VisualEditor on a local wiki, please see https://www.mediawiki.org/wiki/Extension:VisualEditor
For information about running tests and contributing code to VisualEditor, see CONTRIBUTING.md. Patch submissions are reviewed and managed with Gerrit. There is also API documentation available for the VisualEditor.