The about: URI Scheme

Many web browsers implement an internal URI scheme to access built-in features, advanced functionality, default warning/error messages and "easter eggs". In most cases, the scheme name for these URIs is "about:".

The following are lists of about: URIs available in recent versions of Internet Explorer, Firefox / Seamonkey & other Mozilla compatible browsers, and Google Chrome & Chromium.

Internet Explorer
More information: http://support.microsoft.com/kb/183978

Customized "about:" URLs can be defined for Internet Explorer in the Windows Registry under the following path:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\AboutURLs

The following list is mainly for versions 6 (SP2) and above.

about:blank	Displays nothing -- a blank page.
about:DesktopItemNavigationFailure	Displays the default error page used when the browser can not navigate to the provided local desktop URI.
about:Home	Displays the current defined home page (the page that loads if you click Internet Explorer's Home button in the page navigation toolbar)
about:mozilla	Displays an empty blue webpage. Removed in Windows XP SP2, but can still be accessed using res://mshtml.dll/about.moz
about:NavigationCanceled	Displays the default error page used when the browser aborts loading a page (user cancelled).
about:NavigationFailure	Displays the default error page used when the browser can not navigate to the provided URI.
about:NoAdd-ons	IE 7 and above: Displays the warning page used when the browser starts up in safe mode (add-ons disabled).
about:NoAdd-onsInfo	IE 7 and above: Displays further help information about running the browser with add-ons disabled.
about:OfflineInformation	Displays the warning page used when the browser is in offline mode.
about:PostNotCached	Displays the warning page used when the browser can not reload a page without resending previously submitted form data.
about:SecurityRisk	Displays the warning page used when the browser prevents loading a page due to user-configured security settings that are too low.
about:Tabs	IE 7 and above: Displays the help information page about using tabs.
about:inprivate	IE 8 and above: Displays the help information page for the InPrivate browsing feature.

Mozilla products: Firefox, Seamonkey, etc.
More information: http://kb.mozillazine.org/About_protocol_links

about:	Displays a product information page, including name, logo, version, links to licensing information, etc.
about:about	Displays a list of about: URIs available (not available in Firefox)
about:blank	Displays nothing -- a blank page.
about:bloat	Available only in developmental versions of Mozilla-based products.
about:buildconfig	Displays information about options used to build/compile the web browser software.
about:cache	Displays cache entries & statistics.
about:cache-entry	Displays information about a specific cache-entry. The cache entry must be identified within a querystring. Generally you would not enter this yourself, as the links using this URI are generated by the about:cache viewer.
about:config	Allows you to access and modify all configurable options available in the software, including advanced/experimental settings.
about:credits	Displays an alphabetically organized list of contributors.
about:licence	Displays licence information
about:license	An alias that performs the same function as the above about:licence URI.
about:logo	Displays the logo image used in the software.
about:mozilla	Displays an page containing a excerpt from "The Book of Mozilla" (not an actual book)
about:neterror	Displays a generic built-in error page (Cannot Complete Request)
about:plugins	Lists all available plugins, including details such as versions, file locations, etc.
about:robots	Firefox 3.0 easter egg appearing after March 8th, 2008
about:blocked	Firefox 3.0 blocked information page used by the malware protection feature.
about:rights	Shows licensing information for the Ubuntu 8.10 shipped version of Firefox.

Google Chrome / Chromium
More information: http://googlesystem.blogspot.com/2008/09/google-chromes-about-pages.html

about:memory	Lists the browser's memory usage details.
about:stats	Lists counter and timing statistics of internal methods/functions.
about:network	Network I/O tracking & status tool.
about:internets	An easter egg which makes reference to the "internets" Bushism and "series of tubes" Internet memes
about:histograms	Displays text-based histograms measuring the performance of internal browser methods/functions.
about:dns	Displays DNS lookup performance and caching statistics.
about:cache	Displays a list of webpage resources stored in the local browser cache.
about:crash	Displays the "sad tab" error page -- used when a page causes the current sandboxed browser process to crash (Aw, Snap! Something went wrong while displaying this webpage...).
about:plugins	Lists all available plugins, including details such as versions, file locations, etc.
about:version	Displays version information for various components.