The MDN (Mozilla Developer Network) is a much more comprehensive, accurate and up-to-date resource than W3Schools. There’s a full justification over at http://w3fools.com/ — it’s clear that as web developers, we would strongly prefer quality results over advertising-driven, misleading resources. For beginners, it’s also important that W3Schools not be confused for an official W3C (World Wide Web Consortium) subsidiary—there exists no affiliation between them, and W3C members have often requested that W3Schools make this explicit, to no avail.

Nevertheless, W3Schools continues to show up as the first result for many searches including HTML, JavaScript and CSS-related terms. The undersigned are petitioning Google to adjust the search ranking of W3Schools to promote the use of better resources such as the MDN, webplatform.org, SitePoint and the official W3C wiki.