Have you ever clicked on a link only to land on an empty webpage with the message "Error 404" or "404 Not Found?" If so, you're not alone. There are several reasons ...

The Wikimedia Foundation suffered a security incident today after a self-propagating JavaScript worm began vandalizing pages and modifying user scripts across multiple wikis.

Learn how the DOM structures your page, how JavaScript can change it during rendering, and how to verify what Google actually sees.