VisualEditor and Parsoid work together to provide a visual editor for wiki pages. Parsoid is used 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. Both projects are written in JavaScript. Parsoid runs on Node.js while VisualEditor runs in a web browser. For more information about these projects, check out the wiki: * http://www.mediawiki.org/wiki/VisualEditor * http://www.mediawiki.org/wiki/Parsoid