Gecko as its layout engine, all Firefox-specific about: URIs worked in it. After the adoption of WebKit as its layout engine, only the following URIs are supported. Netscape The about: URL originated in and has existed in all versions of Netscape browsers. It was originally added as an Easter egg to display information about the development team. Older versions of the Netscape browser have an about:people URI that was similar to about:credits above, but it would redirect to Netscape's active employee listing. In addition, about:username, where username is the username of a Netscape employee, would redirect to the Netscape homepage of the employee specified. For example, about:jwz would redirect to http://people.netscape.com/jwz/' (not an active link). Not all employee pages were accessible through this scheme. Only developers who knew which file in the source tree and the encoding scheme used to obfuscate the directory of employee about entries could add their names. Many other about: easter eggs existed, including the famous about:mozilla, and other less known ones that showed pictures of the Netscape mascot Mozilla in various foreign garb, such as about:deutsch'' showing Mozilla in Lederhosen. Some versions of Netscape would display the browser history for the about:global URI. Others In Konqueror, any about URI except about:blank and about:plugins redirects to about:konqueror, which shows a friendly ‘start’ and navigation page. In Internet Explorer for Mac 5 was an offline Easter egg, accessible by typing ‘about:tasman’, showing the Acid1 test with the text replaced by the names of the developers. Safari only recognizes about:blank. Microsoft Outlook supports an additional outlook:today URI, which shows the Outlook Today Screen. This screen shows messages, tasks and appointments; it is also accessible from Internet Explorer. Outlook recognizes about:blank too, but no other "about:" URIs. Notes References External links - The "about" URI Scheme About protocol links in Mozilla and Mozilla Firefox. about redirectors' source code in Firefox Web browsers Mozilla URI schemes