About: URI scheme
Encyclopedia
about is an internal URI scheme
(also known as a "URL
scheme" or, erroneously, "protocol") in various web browser
s to display certain built-in functions. It is not an officially registered scheme, and has no standard syntax.
In early versions of Netscape
, any address beginning
,
(e.g.
defined by RFC 2397. Still other versions of Netscape would return various phrases in response to an unknown
) or "Homey don't play dat!" (from a recurring skit
on the TV show In Living Color
).
The most commonly implemented about URIs are
uses URIs beginning with opera for similar purposes, and many about URIs will be translated into an appropriate opera URI if entered; an exception is
is disabled for all addresses in the about or opera URI schemes as a security feature. These pages can, however, be styled using local stylesheets
.
None of these functions, except the about:blank combination, work in the Nintendo DS
version of the Opera browser, the Nintendo DS Browser
.
. It is therefore possible that some of the listed addresses will not work on a particular computer. For example "about:mozilla
" was removed in SP2 (although the page can still be found at "res://mshtml.dll/about.moz"). These about addresses are sometimes used for spyware and adware, most notably in CoolWebSearch
, which made about:blank display advertisements.
Note: Any "about:" URI is accepted, but only a page with a blank source is returned, as with the "about:blank" of other browsers. Similar to Safari.
used Gecko
as its layout engine, the general and Mozilla-specific about: addresses worked as in Mozilla Firefox
. Since WebKit
became Epiphany's layout engine, only these addresses are supported:
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.
, an additional
URI scheme
In the field of computer networking, a URI scheme is the top level of the Uniform Resource Identifier naming structure. All URIs and absolute URI references are formed with a scheme name, followed by a colon character , and the remainder of the URI called the scheme-specific part...
(also known as a "URL
Uniform Resource Locator
In computing, a uniform resource locator or universal resource locator is a specific character string that constitutes a reference to an Internet resource....
scheme" or, erroneously, "protocol") in various web browser
Web browser
A web browser is a software application for retrieving, presenting, and traversing information resources on the World Wide Web. An information resource is identified by a Uniform Resource Identifier and may be a web page, image, video, or other piece of content...
s to display certain built-in functions. It is not an officially registered scheme, and has no standard syntax.
In early versions of Netscape
Netscape Navigator
Netscape Navigator was a proprietary web browser that was popular in the 1990s. It was the flagship product of the Netscape Communications Corporation and the dominant web browser in terms of usage share, although by 2002 its usage had almost disappeared...
, any address beginning
about: which wasn't recognised as a built-in command would simply result in the text after the colon being displayed. Similarly, in early versions of Internet ExplorerInternet Explorer
Windows Internet Explorer is a series of graphical web browsers developed by Microsoft and included as part of the Microsoft Windows line of operating systems, starting in 1995. It was first released as part of the add-on package Plus! for Windows 95 that year...
,
about: followed by a string of HTMLHTML
HyperText Markup Language is the predominant markup language for web pages. HTML elements are the basic building-blocks of webpages....
(e.g.
about:<em>hello world</em> Data: URI scheme
The data URI scheme is a URI scheme that provides a way to include data in-line in web pages as if they were external resources. It tends to be simpler than other inclusion methods, such as MIME with cid or mid URIs. Data URIs are sometimes called Uniform Resource Locators, although they do not...
defined by RFC 2397. Still other versions of Netscape would return various phrases in response to an unknown
about address, including "Whatchew talkin' 'bout, Willis?" (a catch phrase from the TV show Diff'rent StrokesDiff'rent Strokes
Diff'rent Strokes is an American television sitcom that aired on NBC from November 3, 1978 to May 4, 1985, and on ABC from September 27, 1985 to March 7, 1986...
) or "Homey don't play dat!" (from a recurring skit
Sketch comedy
A sketch comedy consists of a series of short comedy scenes or vignettes, called "sketches," commonly between one and ten minutes long. Such sketches are performed by a group of comic actors or comedians, either on stage or through an audio and/or visual medium such as broadcasting...
on the TV show In Living Color
In Living Color
In Living Color is an American sketch comedy television series, which originally ran on the Fox Network from April 15, 1990 to May 19, 1994. Brothers Keenen and Damon Wayans created, wrote, and starred in the program. The show was produced by Ivory Way Productions in association with 20th Century...
).
The most commonly implemented about URIs are
about:blank, which displays a blank HTML document, and simply about:, which may display information about the browser. OperaOpera (web browser)
Opera is a web browser and Internet suite developed by Opera Software with over 200 million users worldwide. The browser handles common Internet-related tasks such as displaying web sites, sending and receiving e-mail messages, managing contacts, chatting on IRC, downloading files via BitTorrent,...
uses URIs beginning with opera for similar purposes, and many about URIs will be translated into an appropriate opera URI if entered; an exception is
about:blank, which is not translated.Note: In more recent versions of Internet Explorer, many of the following do not work or have been removed.
Standardisation
In 2010, and onwards, there were efforts to standardise the about URI scheme, and define the processing requirements for some specific URIs. Note that Opera ASA, the proponents, had long used and advocated alternative browser specific URIs. The about URIs that are known to be defined for specific purposes are listed below.| Address | Purpose |
|---|---|
| Returns a blank HTML document with the media type text/html and character encoding UTF-8. This is widely used to load blank pages into browsing contexts, such as iframes within HTML, which may then be modified by scripts. | |
| about:legacy-compat | A reserved, though unresolvable address defined within HTML5 intended for use in the DOCTYPE designed for compatibility with some legacy authoring tools, such as XSLT, which may not be capable of outputting the more common, shorter alternative that lacks both the PUBLIC and SYSTEM identifiers. <!DOCTYPE html SYSTEM "about:legacy-compat">. |
| about:srcdoc | A reserved, though unresolvable address defined within HTML5 intended to be the address navigated to within iframes whose content comes from the srcdoc attribute |
Common about: addresses
| Addresses | Mozilla Mozilla Application Suite The Mozilla Application Suite is a cross-platform integrated Internet suite. Its development was initiated by Netscape Communications Corporation, before their acquisition by AOL. It is based on the source code of Netscape Communicator... / SeaMonkey SeaMonkey SeaMonkey is a free and open source cross-platform Internet suite. It is the continuation of the former Mozilla Application Suite, based on the same source code... |
Mozilla Firefox Mozilla Firefox Mozilla Firefox is a free and open source web browser descended from the Mozilla Application Suite and managed by Mozilla Corporation. , Firefox is the second most widely used browser, with approximately 25% of worldwide usage share of web browsers... |
Google Chrome Google Chrome Google Chrome is a web browser developed by Google that uses the WebKit layout engine. It was first released as a beta version for Microsoft Windows on September 2, 2008, and the public stable release was on December 11, 2008. The name is derived from the graphical user interface frame, or... |
Konqueror Konqueror Not to be confused with the Conqueror web browser.Konqueror is a web browser and file manager that provides file-viewer functionality for file systems such as local files, files on a remote ftp server and files in a disk image. It is a core part of the KDE desktop environment... |
Opera Opera (web browser) Opera is a web browser and Internet suite developed by Opera Software with over 200 million users worldwide. The browser handles common Internet-related tasks such as displaying web sites, sending and receiving e-mail messages, managing contacts, chatting on IRC, downloading files via BitTorrent,... |
Safari Safari (web browser) Safari is a web browser developed by Apple Inc. and included with the Mac OS X and iOS operating systems. First released as a public beta on January 7, 2003 on the company's Mac OS X operating system, it became Apple's default browser beginning with Mac OS X v10.3 "Panther". Safari is also the... |
Internet Explorer Internet Explorer Windows Internet Explorer is a series of graphical web browsers developed by Microsoft and included as part of the Microsoft Windows line of operating systems, starting in 1995. It was first released as part of the add-on package Plus! for Windows 95 that year... |
MSN Explorer MSN Explorer MSN Explorer is a web browser, developed by Microsoft, that integrates MSN and Windows Live features such as Windows Live Hotmail and Windows Live Messenger with a web browser. To make use of these services requires a Windows Live ID... |
|---|---|---|---|---|---|---|---|---|
| about: | Shows version information and copyright information | Translated to "about:konqueror" | Translated to "opera:about" | Shows a blank page | ||||
| about:about | Lists all the about: addresses (Firefox since version 4.0) |
Translated to "about:konqueror" | Translated to "opera:about" | Shows nothing but the text:"about" | ||||
| about:blank | Shows a blank HTML document | |||||||
| about:plugins | Shows the filename, MIME type, description, suffix, and status of all installed plug-ins | Translated to "opera:plugins" | ||||||
| about:cache | Shows information about the Cache Service. | Lists the URIs of pages stored within the cache, with each linking to view-cache:uri that provides more information about its content. |
Translated to "about:konqueror" | Translated to "opera:cache" | ||||
| about:mozilla | Shows a page from the fictional Book of Mozilla The Book of Mozilla The Book of Mozilla is a computer Easter egg found in the Netscape and Mozilla series of web browsers.It is viewed by directing the browser to about:mozilla.There is no real book entitled The Book of Mozilla... . In some versions of Netscape, also replaced the meteors in the standard Netscape throbber Throbber A throbber is a graphic found in a graphical user interface of a computer program that animates to show the user that the program is performing an action .-Typical characteristics:... with a large fire-breathing lizard. |
Translated to "about:konqueror" | The Windows version of IE showed a blank HTML document with blue Blue Blue is a colour, the perception of which is evoked by light having a spectrum dominated by energy with a wavelength of roughly 440–490 nm. It is considered one of the additive primary colours. On the HSV Colour Wheel, the complement of blue is yellow; that is, a colour corresponding to an equal... background color. Possibly a joke reference to the "Blue Screen of Death Blue Screen of Death To forse a BSOD Open regedit.exe,Then search: HKLM\SYSTEM\CurrentControlSet\services\i8042prt\ParametersThen make a new DWORD called "CrashOnCtrlScroll" And set the value to 1.... ." Removed in Windows XP Windows XP Windows XP is an operating system produced by Microsoft for use on personal computers, including home and business desktops, laptops and media centers. First released to computer manufacturers on August 24, 2001, it is the second most popular version of Windows, based on installed user base... SP2 Service pack A service pack is a collection of updates, fixes or enhancements to a software program delivered in the form of a single installable package. Many companies, such as Microsoft or Autodesk, typically release a service pack when the number of individual patches to a given program reaches a certain ... but it can still be shown by typing "res://mshtml.dll/about.moz" instead. |
|||||
Mozilla-specific about: addresses
Many of these can also be used in Thunderbird, by setting them as the "Mail Start Page". Also, some extensions define additional about: addresses not listed here.| Addresses | Mozilla Application Suite Mozilla Application Suite The Mozilla Application Suite is a cross-platform integrated Internet suite. Its development was initiated by Netscape Communications Corporation, before their acquisition by AOL. It is based on the source code of Netscape Communicator... / SeaMonkey SeaMonkey SeaMonkey is a free and open source cross-platform Internet suite. It is the continuation of the former Mozilla Application Suite, based on the same source code... |
Mozilla Firefox Mozilla Firefox Mozilla Firefox is a free and open source web browser descended from the Mozilla Application Suite and managed by Mozilla Corporation. , Firefox is the second most widely used browser, with approximately 25% of worldwide usage share of web browsers... |
|---|---|---|
| about:bloat | Displays BloatView output (disabled in release builds). Superseded by about:memory on Gecko 1.9.2 | |
| about:blocked | Shows the malware Malware Malware, short for malicious software, consists of programming that is designed to disrupt or deny operation, gather information that leads to loss of privacy or exploitation, or gain unauthorized access to system resources, or that otherwise exhibits abusive behavior... protection page used when the browser identifies a page as not safe for viewing. Firefox 3+ |
|
| about:addons | Shows installed addons, plugins, themes, and provides an interface for installing new addons. Firefox 4+, SeaMonkey 2.1+ | |
| about:buildconfig | Shows the arguments and options used to compile the build in use | |
| about:cache | Shows information about the Cache Service. Number of entries, location of cache, size of cache, etc. for both memory and disk cache. | |
| about:cache?device=memory | Shows individual entries in memory | |
| about:cache?device=disk | Shows individual entries on disk | |
| about:cache?device=offline | Shows individual entries for offline viewing. Gecko 1.9+ | |
| about:cache-entry | Shows information about a cache entry. Used in about:cache links. Requires parameters. | |
| about:certerror | Shows the error page used when an SSL/TLS Transport Layer Security Transport Layer Security and its predecessor, Secure Sockets Layer , are cryptographic protocols that provide communication security over the Internet... certificate is untrusted or otherwise invalid. |
|
| about:config | Shows an interface for viewing and setting a wide variety of configuration variables, many of which are not otherwise accessible through the GUI Graphical user interface In computing, a graphical user interface is a type of user interface that allows users to interact with electronic devices with images rather than text commands. GUIs can be used in computers, hand-held devices such as MP3 players, portable media players or gaming devices, household appliances and... (options panels) |
|
| about:crashes | Shows details of crashes submitted by Mozilla's crash reporter. Firefox 3+, SeaMonkey 2.0+ | |
| about:credits | Shows a list of all those who contributed to Mozilla | |
| about:feeds | Shows the page used when clicking the rss feed icon in the address bar. | |
| about:home | Shows the Firefox 4 default home page. | |
| about:jetpack | Shows an interface for viewing and setting the JetPack extension https://jetpack.mozillalabs.com/ | |
| about:licence | In the British English localised Internationalization and localization In computing, internationalization and localization are means of adapting computer software to different languages, regional differences and technical requirements of a target market... version, shows the content of about:license but with all occurrences of license used as a noun Noun In linguistics, a noun is a member of a large, open lexical category whose members can occur as the main word in the subject of a clause, the object of a verb, or the object of a preposition .Lexical categories are defined in terms of how their members combine with other kinds of... replaced with licence (see American and British English spelling differences American and British English spelling differences One of the ways in which American English and British English differ is in spelling.-Historical origins:In the early 18th century, English spelling was not standardized. Differences became noticeable after the publishing of influential dictionaries... ). Not available in Firefox 4 |
|
| about:license | Shows the Mozilla Public License Mozilla Public License The Mozilla Public License is a free and open source software license. Version 1.0 was developed by Mitchell Baker when she worked as a lawyer at Netscape Communications Corporation and version 1.1 at the Mozilla Foundation... (and the Netscape Public License Netscape Public License The Netscape Public License is a free software license, the license under which Netscape Communications Corporation originally released Mozilla.... ) for the piece of software. Gecko 1.8+ |
|
| about:logo | Shows the logo used on the about: screen | |
| about:memory | Shows memory usage. Firefox 3.6+ | |
| about:mozilla | Easter egg: Shows a verse from The Book of Mozilla The Book of Mozilla The Book of Mozilla is a computer Easter egg found in the Netscape and Mozilla series of web browsers.It is viewed by directing the browser to about:mozilla.There is no real book entitled The Book of Mozilla... |
|
| about:neterror | Shows the error page used when the browser could not access the requested path. | |
| about:permissions | Shows permissions for sites on Firefox 6.0a1. | |
| about:plugins | Shows installed, currently enabled plug-ins. | |
| about:privatebrowsing | Can be used to switch to private browsing mode, shows a message indicating that Firefox will not remember any history for the current session. Note: It does not show URI on the address bar. | |
| about:rights | Shows licensing information. | |
| about:robots | Easter egg, beginning with March 8, 2008 trunk builds. The title of a window contains a citation from The Day the Earth Stood Still. https://bugzilla.mozilla.org/show_bug.cgi?id=417302 | |
| about:sessionrestore | Shows an interface for viewing about last session | |
| about:support | Shows troubleshooting information. Firefox 3.6+, SeaMonkey 2.1+ | |
Flock-specific about: addresses
Beginning in Flock 0.9, Flock introduced a feature called My World, a place where the user's favorites, RSS feeds and favorite media can be found.| Address | Flock Flock (web browser) Flock was a web browser that specialized in providing social networking and Web 2.0 facilities built into its user interface.Earlier versions of Flock used the Gecko HTML rendering engine by Mozilla.... |
|---|---|
| about:myworld | Shows the My World page. |
| about:tutorial | Shows the Flock tutorial page. |
| about:mozilla | Shows a different version of The Book of Mozilla The Book of Mozilla The Book of Mozilla is a computer Easter egg found in the Netscape and Mozilla series of web browsers.It is viewed by directing the browser to about:mozilla.There is no real book entitled The Book of Mozilla... against a blue screen. |
Opera-specific about: addresses
about is an alias for opera, therefore all these addresses also work with about prefixed. User JavaScriptJavaScript
JavaScript is a prototype-based scripting language that is dynamic, weakly typed and has first-class functions. It is a multi-paradigm language, supporting object-oriented, imperative, and functional programming styles....
is disabled for all addresses in the about or opera URI schemes as a security feature. These pages can, however, be styled using local stylesheets
Cascading Style Sheets
Cascading Style Sheets is a style sheet language used to describe the presentation semantics of a document written in a markup language...
.
None of these functions, except the about:blank combination, work in the Nintendo DS
Nintendo DS
The is a portable game console produced by Nintendo, first released on November 21, 2004. A distinctive feature of the system is the presence of two separate LCD screens, the lower of which is a touchscreen, encompassed within a clamshell design, similar to the Game Boy Advance SP...
version of the Opera browser, the Nintendo DS Browser
Nintendo DS Browser
The Nintendo DS Browser is a version of the Opera web browser for use on the Nintendo DS, developed by Opera Software and Nintendo. The Nintendo DS Browser comes in separate versions for the Nintendo DS and the Nintendo DS Lite; this is due to differing physical size requirements for the memory...
.
| Addresses | Opera Opera (web browser) Opera is a web browser and Internet suite developed by Opera Software with over 200 million users worldwide. The browser handles common Internet-related tasks such as displaying web sites, sending and receiving e-mail messages, managing contacts, chatting on IRC, downloading files via BitTorrent,... |
|---|---|
| opera:blank | Maps to about:blank |
| opera:about | Provides info about the browser and the configured paths. |
| about:opera | Maps to opera:about |
| opera:cache | Shows the content of the cache. |
| opera:config | (Opera 9.0 and newer) Shows a page that allows changing of numerous browser preferences, many of which cannot be accessed through the normal Preferences window |
| opera:drives | (Operating system specific) Shows the local drives of the host system. |
| opera:history | Shows the content of the browser history. |
| opera:historysearch | (Opera 9.5 and newer) Shows the start page of internal search engine for the browser history. |
| opera:plugins | Shows installed plug-ins. Opera 11 and newer allow you to disable individual plug-ins from this page. |
| opera:button | Defines a custom button as a set of Opera actions. (Note: This does not work directly, you need to specify all button parametres as on CustomButtons.) |
| opera:help | Shortcut to the help directory. This can be either local or external. |
| opera:debug | (Opera 9.5 and newer) Shows a page that allows changing of settings for remote debug of Opera via Opera Dragonfly Opera Dragonfly Opera Dragonfly is a full-featured development and debugging tool integrated into the Opera browser.It supports debugging JavaScript, viewing the DOM, monitoring network traffic, previewing resources, editing colors, etc... |
| opera:memdebug | (Opera 9.5 and newer) Shows debug information about memory usage. |
| opera:webstorage | (Opera 10.5 and newer) Shows information Web Storage (see HTML5). |
| opera:webdatabases | (Opera 10.5 and newer) Shows information Web Storage databases (see HTML5). |
Internet Explorer-specific about: addresses
Internet Explorer about addresses are configurable in WindowsMicrosoft Windows
Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...
. It is therefore possible that some of the listed addresses will not work on a particular computer. For example "about:mozilla
The Book of Mozilla
The Book of Mozilla is a computer Easter egg found in the Netscape and Mozilla series of web browsers.It is viewed by directing the browser to about:mozilla.There is no real book entitled The Book of Mozilla...
" was removed in SP2 (although the page can still be found at "res://mshtml.dll/about.moz"). These about addresses are sometimes used for spyware and adware, most notably in CoolWebSearch
CoolWebSearch
CoolWebSearch is a well-known spyware program that installs itself on Microsoft Windows based computers. It first appeared in May 2003.- Effects :...
, which made about:blank display advertisements.
| Address | Internet Explorer 6 (SP2) | Internet Explorer 7 Internet Explorer 7 Windows Internet Explorer 7 is a web browser released by Microsoft in October 2006. Internet Explorer 7 is part of a long line of versions of Internet Explorer and was the first major update to the browser in more than 5 years... |
Internet Explorer 8 Internet Explorer 8 Windows Internet Explorer 8 is a web browser developed by Microsoft in the Internet Explorer browser series. The browser was released on March 19, 2009 for Windows XP, Windows Server 2003, Windows Vista, Windows Server 2008, and Windows 7. Both 32-bit and 64-bit builds are available... |
|---|---|---|---|
| about:home | Displays the user's home page. | ||
| about:blank | Displays the blank page. | ||
| about:desktopitemnavigationfailure | Displays "navigation cancelled" page. | ||
| about:navigationcanceled | Displays "navigation cancelled" page. | ||
| about:navigationfailure | Displays "navigation cancelled" page. | ||
| about:noadd-ons | Displays information page when add-ons are disabled. | ||
| about:noadd-onsinfo | Displays information page about the effects when you use add-ons. | ||
| about:offlineinformation | Informs the user that the current page can not be viewed off line. | ||
| about:postnotcached | Informs the user that to refresh the current page, information entered in a form will have to be re-posted. | ||
| about:securityrisk | Informs the user not to browse with the current security settings because they may be harmful to the computer. | ||
| about:tabs | Informs the user about tabbed browsing. It is also loaded when a new tab is created if the "Open home page for new tabs instead of a blank page" setting is enabled | ||
| about:inprivate | Informs the user about InPrivate Browsing. It is loaded when InPrivate Browsing is initiated. | ||
Google Chrome-specific about: addresses
| Address | Google Chrome Google Chrome Google Chrome is a web browser developed by Google that uses the WebKit layout engine. It was first released as a beta version for Microsoft Windows on September 2, 2008, and the public stable release was on December 11, 2008. The name is derived from the graphical user interface frame, or... |
|---|---|
| about:cache | Shows the content of the cache. |
| about:crash | Displays "Aw, snap!" crash notification page. |
| about:credits | Displays the list of free and open source software used in the browser, and their associated licences. |
| about:dns | Displays the DNS records |
| about:flags | See about:labs |
| about:histograms | Displays histograms |
| about:inducebrowsercrashforrealz | Crashes the Google Chrome browser. This is designed for developers to test what happens when the Google Chrome browser crashes. |
| about:internets | Displays a page entitled "Don't Clog the Tubes! Series of tubes "Series of tubes" is a phrase coined originally as an analogy by then-United States Senator Ted Stevens to describe the Internet in the context of opposing network neutrality. On June 28, 2006, he used this metaphor to criticize a proposed amendment to a committee bill... " which renders a page with an animation of the Microsoft Windows Microsoft Windows Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal... "3D Pipes" screensaver. Does not work on Windows Vista Windows Vista Windows Vista is an operating system released in several variations developed by Microsoft for use on personal computers, including home and business desktops, laptops, tablet PCs, and media center PCs... due to the pipes screen saver no longer being supported for releases after the 2.0.169.1 release. |
| about:kill | Same as about:crash, but with a violet background color and the message "He's Dead, Jim!" Occurs when the OS runs out of memory or the browser is killed by an external cause, such as the OS shutting down. |
| about:labs | Displays a page for testing features. Moved to about:flags in Chrome Dev channel 8.0.552.11 |
| about:memory | Displays the process manager |
| about:net-internals | Provides an interface for monitoring the network usage and performance statistics |
| about:plugins | Shows installed plug-ins. |
| about:stats | Displays statistics about processes. At the top of the page, it states "Shhh! This page is secret!" |
| about:shorthang | Hangs the tab's process, making it become unresponsive. This is designed for testing the hanging protection. |
| about:version | Displays version information, same as about: |
Note: Any "about:" URI is accepted, but only a page with a blank source is returned, as with the "about:blank" of other browsers. Similar to Safari.
Konqueror
Note: Anyabout URI except about:blank and about:plugins redirects to about:konqueror.
| Address | Konqueror Konqueror Not to be confused with the Conqueror web browser.Konqueror is a web browser and file manager that provides file-viewer functionality for file systems such as local files, files on a remote ftp server and files in a disk image. It is a core part of the KDE desktop environment... |
|---|---|
| about:konqueror | Shows a friendly 'start' and navigation page |
Epiphany
Note: When EpiphanyEpiphany (web browser)
Epiphany is an open source web browser for the GNOME desktop environment. The browser is a descendant of Galeon, and was created after developer disagreements about Galeon's growing complexity...
used Gecko
Gecko (layout engine)
Gecko is a free and open source layout engine used in many applications developed by Mozilla Foundation and the Mozilla Corporation , as well as in many other open source software projects....
as its layout engine, the general and Mozilla-specific about: addresses worked as in Mozilla Firefox
Mozilla Firefox
Mozilla Firefox is a free and open source web browser descended from the Mozilla Application Suite and managed by Mozilla Corporation. , Firefox is the second most widely used browser, with approximately 25% of worldwide usage share of web browsers...
. Since WebKit
WebKit
WebKit is a layout engine designed to allow web browsers to render web pages. WebKit powers Google Chrome and Apple Safari and by October 2011 held over 33% of the browser market share between them. It is also used as the basis for the experimental browser included with the Amazon Kindle ebook...
became Epiphany's layout engine, only these addresses are supported:
| Address | Epiphany Epiphany (web browser) Epiphany is an open source web browser for the GNOME desktop environment. The browser is a descendant of Galeon, and was created after developer disagreements about Galeon's growing complexity... |
|---|---|
| about:blank | Displays the blank page. |
| about:plugins | Shows installed plug-ins. |
| about:epiphany | Displays the following message: |
| about:applications | interface for managing web applications, supported since release 3.2, to be removed in release 3.4. |
Netscape (historic)
- Older versions of the NetscapeNetscapeNetscape Communications is a US computer services company, best known for Netscape Navigator, its web browser. When it was an independent company, its headquarters were in Mountain View, California...
browser have an about:people URL 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 tohttp://people.netscape.com/jwz/ (not an active link) http://www.yikes.com/netscape/people.html http://www.jwz.org/gruntle/blowme.html. - 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 address
Internet Explorer for Mac OS 5 (historic)
In the Internet Explorer for MacInternet Explorer for Mac
Internet Explorer for Mac was a proprietary web browser developed by Microsoft for the Macintosh platform. Initial versions were developed from the same code base as Internet Explorer for Windows...
5 was an offline Easter egg
Easter egg (media)
Image:Carl Oswald Rostosky - Zwei Kaninchen und ein Igel 1861.jpg|250px|thumb|right|Example of Easter egg hidden within imagerect 467 383 539 434 desc none...
, accessible by typing 'about:tasman
Tasman (layout engine)
Tasman was a layout engine developed by Microsoft for inclusion in the Macintosh version of Internet Explorer 5. Tasman was an attempt to improve support for web standards, as defined by the World Wide Web Consortium. At the time of its release, Tasman was seen as the layout engine with the best...
', showing the Acid1
Acid1
Acid1, originally called the Box Acid Test, is a test page for web browsers. It was developed in October 1998 and was important in establishing baseline interoperability between early web browsers, especially for the Cascading Style Sheets 1.0 specification...
test with the text replaced by the names of the developers.
Safari
Anyabout URI is accepted, but only a page with a blank source is returned, as with the about:blank of other browsers.Microsoft Outlook
In Microsoft OutlookMicrosoft Outlook
Microsoft Outlook is a personal information manager from Microsoft, available both as a separate application as well as a part of the Microsoft Office suite...
, an additional
outlook:today URI was added, which showed the Outlook Today Screen (it shows messages, tasks and appointments and is also accessible from IE). Also, although about:blank is supported, anything else (including about:about) typed after about: would show that text as a web page in the browser.External links
- IETF draft specification for the about: URI scheme
- About protocol links in Mozilla and Mozilla Firefox.
- about redirectors' source code in Firefox