Internet Explorer

Internet Explorer (formerly Microsoft Internet Explorer and Windows Internet Explorer, commonly abbreviated as IE or MSIE) is a retired series of graphical web browsers developed by Microsoft that were used in the Windows line of operating systems. While IE has been discontinued on most Windows editions, it remains supported on certain editions of Windows, such as Windows 10 LTSB/LTSC.https://techcommunity.microsoft.com/t5/windows-it-pro-blog/internet-explorer-11-desktop-app-retirement-faq/ba-p/2366549
Starting in 1995, it was first released as part of the add-on package Plus! for Windows 95 that year. Later versions were available as free downloads or in-service packs and included in the original equipment manufacturer (OEM) service releases of Windows 95 and later versions of Windows. Microsoft spent over US$100 million per year on Internet Explorer in the late 1990s,https://web.archive.org/web/20210221021334/https://www.cnet.com/news/ with over 1,000 people involved in the project by 1999.https://web.archive.org/web/20150626112836/http://www.citeworld.com/article/2147006/consumerization/internet-explorer-rise-fall-rehabilitation.htmlhttps://www.justice.gov/atr/cases/f2600/2613-1.htm New feature development for the browser was discontinued in 2016https://web.archive.org/web/20160716113141/https://developer.microsoft.com/en-us/microsoft-edge/platform/faq/ and ended support on June 15, 2022 for Windows 10 Semi-Annual Channel (SAC), in favor of its successor, Microsoft Edge.
==Versions==
 List of versions of Internet Explorer
Name 	Release Date 	Description
Internet Explorer 1 	1994 	The Internet Explorer project was started in the summer of 1994 by Thomas Reardon, who, according to former project lead Ben Slivka, used source code from Spyglass, Inc. Mosaic, which was an early commercial web browser with formal ties to the pioneering National Center for Supercomputing Applications (NCSA) Mosaic browser.
Internet Explorer 2 	November 22, 1995	Internet Explorer 2 is the second major version of Internet Explorer, released on November 22, 1995, for Windows 95 and Windows NT, and on April 23, 1996, for Apple Macintosh"Chronology of Personal Computers (1996)" - www.islandnet.com. and Windows 3.1."Microsoft Internet Explorer Web Browser Available on All Major Platforms, Offers Broadest International Support" - Stories (April 30th, 1996)
Internet Explorer 3 	August 13, 1996 	Internet Explorer 3 is the third major version of Internet Explorer, released on August 13, 1996, for Microsoft Windows and on January 8, 1997, for Apple Mac OS.
Internet Explorer 4 	September 1997 	Internet Explorer 4 is the fourth major version of Internet Explorer, released in September 1997 for Microsoft Windows, Mac OS, Solaris, and HP-UX. It was the first version of Internet Explorer to use the Trident web engine.
Internet Explorer 5 	March 18, 1999 	Internet Explorer 5 is the fifth major version of Internet Explorer, released on March 18, 1999, for Windows 3.1, Windows NT 3, Windows 95, Windows NT 4.0 SP3, Windows 98, Mac OS X (up to v5.2.3), Classic Mac OS (up to v5.1.7), Solaris and HP-UX (up to 5.01 SP1).
Internet Explorer 6 	August 24, 2001 	Internet Explorer 6 is the sixth major version of Internet Explorer, released on August 24, 2001, for Windows NT 4.0 SP6a, Windows 98, Windows 2000, Windows ME and as the default web browser for Windows XP and Windows Server 2003.
Internet Explorer 7 	October 18, 2006 	Internet Explorer 7 is the seventh major version of Internet Explorer, released on October 18, 2006, for Windows XP SP2, Windows Server 2003 SP1 and as the default web browser for Windows Vista, Windows Server 2008 and Windows Embedded POSReady 2009. IE7 introduces tabbed browsing.
Internet Explorer 8 	March 19, 2009 	Internet Explorer 8 is the eighth major version of Internet Explorer, released on March 19, 2009, for Windows XP, Windows Server 2003, Windows Vista, Windows Server 2008 and as the default web browser for Windows 7 (later default was Internet Explorer 11) and Windows Server 2008 R2.
Internet Explorer 9 	March 14, 2011 	Internet Explorer 9 is the ninth major version of Internet Explorer, released on March 14, 2011, for Windows 7, Windows Server 2008 R2, Windows Vista Service Pack 2 and Windows Server 2008 SP2 with the Platform Update.
Internet Explorer 10	October 26, 2012 	Internet Explorer 10 is the tenth major version of Internet Explorer, released on October 26, 2012, and is the default web browser for Windows 8 and Windows Server 2012. It became available for Windows 7 SP1 and Windows Server 2008 R2 SP1 in February 2013.
Internet Explorer 11	October 17, 2013 	Internet Explorer 11 is featured in Windows 8.1, Windows Server 2012 R2 and Windows RT 8.1, which was released on October 17, 2013. It includes an incomplete mechanism for syncing tabs. It is a major update to its developer tools, enhanced scaling for high DPI screens, HTML5 prerender and prefetch, hardware-accelerated JPEG decoding, closed captioning, HTML5 full screen, and is the first Internet Explorer to support WebGL and Google's protocol SPDY (starting at v3). This version of IE has features dedicated to Windows 8.1, including cryptography (WebCrypto), adaptive bitrate streaming (Media Source Extensions) and Encrypted Media Extensions.
==Features==
Internet Explorer has been designed to view a broad range of web pages and provide certain features within the operating system, including Microsoft Update. During the height of the browser wars, Internet Explorer superseded Netscape only when it caught up technologically to support the progressive features of the time.http://www.blooberry.com/indexdot/history/netscape.htm
===Standards support ===
Internet Explorer, using the MSHTML (Trident) browser engine: 
*Supports HTML 4.01, parts of HTML5, CSS Level 1, Level 2, and Level 3, XML 1.0, and DOM Level 1, with minor implementation gaps.
*Fully supports XSLT 1.0 as well as an obsolete Microsoft dialect of XSLT often referred to as WD-xsl, which was loosely based on the December 1998 W3C Working Draft of XSL. Support for XSLT 2.0 lies in the future: semi-official Microsoft bloggers have indicated that development is underway, but no dates have been announced.
*Almost full conformance to CSS 2.1 has been added in the Internet Explorer 8 release. The MSHTML browser engine in Internet Explorer 9 in 2011, scored highest in the official W3C conformance test suite for CSS 2.1 of all major browsers.
*Supports XHTML in Internet Explorer 9 (MSHTML Trident version 5.0). Prior versions can render XHTML documents authored with HTML compatibility principles and served with a text/html MIME-type.
*Supports a subset of SVG in Internet Explorer 9 (MSHTML Trident version 5.0), excluding SMIL, SVG fonts and filters.
===Non-standard extensions ===
Internet Explorer has introduced an array of proprietary extensions to many of the standards, including HTML, CSS, and the DOM. This has resulted in several web pages that appear broken in standards-compliant web browsers and has introduced the need for a "quirks mode" to allow for rendering improper elements meant for Internet Explorer in these other browsers.
Internet Explorer has introduced several extensions to the DOM that have been adopted by other browsers.
These include the inner HTML property, which provides access to the HTML string within an element, which was part of IE 5 and was standardized as part of HTML 5 roughly 15 years later after all other browsers implemented it for compatibility,"innerHTML and compatibility" - www.xul.fr. the XMLHttpRequest object, which allows the sending of HTTP request and receiving of HTTP response, and may be used to perform AJAX, and the designMode attribute of the content Document object, which enables rich text editing of HTML documents.Some of these functionalities were not possible until the introduction of the W3C DOM methods. Its Ruby character extension to HTML is also accepted as a module in W3C XHTML 1.1, though it is not found in all versions of W3C HTML.
Microsoft submitted several other features of IE for consideration by the W3C for standardization. These include the 'behavior' CSS property, which connects the HTML elements with JScript behaviors (known as HTML Components, HTC), HTML+TIME profile, which adds timing and media synchronization support to HTML documents (similar to the W3C XHTML+SMIL), and the VML vector graphics file format. However, all were rejected, at least in their original forms; VML was subsequently combined with PGML (proposed by Adobe and Sun), resulting in the W3C-approved SVG format, one of the few vector image formats being used on the web, which IE did not support until version 9."SVG Support Tables" - codedread.com
===Favicon===
Support for favicons was first added in Internet Explorer 5.https://web.archive.org/web/20081217122653/http://msdn.microsoft.com/en-us/library/ms537656(VS.85).aspx Internet Explorer supports favicons in PNG, static GIF and native Windows icon formats. In Windows Vista and later, Internet Explorer can display native Windows icons that have embedded PNG files.http://jeffcode.blogspot.com/2007/12/why-doesnt-favicon-for-my-site-appear.htmlhttps://blogs.msdn.microsoft.com/ieinternals/2013/09/07/fun-with-favicons/
===Usability and accessibility===
Internet Explorer makes use of the accessibility framework provided in Windows. Internet Explorer is also a user interface for FTP, with operations similar to Windows Explorer. Internet Explorer 5 and 6 had a side bar for web searches, enabling jumps through pages from results listed in the side bar.https://www.techrepublic.com/article/internet-explorers-search-assistant-gives-you-plenty-of-search-options/ Pop-up blocking and tabbed browsing were added respectively in Internet Explorer 6 and Internet Explorer 7. Tabbed browsing can also be added to older versions by installing MSN Search Toolbar or Yahoo Toolbar.
===Cache===
Internet Explorer caches visited content in the Temporary Internet Files folder to allow quicker access (or offline access) to previously visited pages. The content is indexed in a database file, known as Index.dat. Multiple Index.dat files exist which index different content—visited content, web feeds, visited URLs, cookies, etc.https://web.archive.org/web/20080112205144/http://blogs.msdn.com/wndp/archive/2006/08/04/WinInet_Index_dat.aspx
Prior to IE7, clearing the cache used to clear the index but the files themselves were not reliably removed, posing a potential security and privacy risk. In IE7 and later, when the cache is cleared, the cache files are more reliably removed, and the index.dat file is overwritten with null bytes.
Caching has been improved in IE9.https://blogs.msdn.microsoft.com/ie/2011/03/17/internet-explorer-9-network-performance-improvements/
===Group Policy===
Internet Explorer is fully configurable using Group Policy. Administrators of Windows Server domains (for domain-joined computers) or the local computer can apply and enforce a variety of settings on computers that affect the user interface (such as disabling menu items and individual configuration options), as well as underlying security features such as downloading of files, zone configuration, per-site settings, ActiveX control behavior and others. Policy settings can be configured for each user and for each machine. Internet Explorer also supports Integrated Windows Authentication.
==Architecture==
Internet Explorer uses a componentized architecture built on the Component Object Model (COM) technology. It consists of several major components, each of which is contained in a separate dynamic-link library (DLL) and exposes a set of COM programming interfaces hosted by the Internet Explorer main executable, iexplore.exe:"Internet Explorer Architecture" - MSDN
*WinInet.dll is the protocol handler for HTTP, HTTPS, and FTP. It handles all network communication over these protocols.
*URLMon.dll is responsible for MIME-type handling and download of web content, and provides a thread-safe wrapper around WinInet.dll and other protocol implementations.
*MSHTML.dll houses the MSHTML (Trident) browser engine introduced in Internet Explorer 4, which is responsible for displaying the pages on-screen and handling the Document Object Model (DOM) of the web pages. MSHTML.dll parses the HTML/CSS file and creates the internal DOM tree representation of it. It also exposes a set of APIs for runtime inspection and modification of the DOM tree. The DOM tree is further processed by a browser engine which then renders the internal representation on screen.
*IEFrame.dll contains the user interface and window of IE in Internet Explorer 7 and above.
*ShDocVw.dll provides the navigation, local caching and history functionalities for the browser.
*BrowseUI.dll is responsible for rendering the browser user interface such as menus and toolbars.
Internet Explorer does not include any native scripting functionality. Rather, MSHTML.dll exposes an API that permits a programmer to develop a scripting environment to be plugged-in and to access the DOM tree.
==Security==
Internet Explorer uses a zone-based security framework that groups sites based on certain conditions, including whether it is an Internet- or intranet-based site as well as a user-editable whitelist. Security restrictions are applied per zone; all the sites in a zone are subject to the restrictions, 
Internet Explorer 6 SP2 onwards uses the Attachment Execution Service of Microsoft Windows to mark executable files downloaded from the Internet as being potentially unsafe. Accessing files marked as such will prompt the user to make an explicit trust decision to execute the file, as executables originating from the Internet can be potentially unsafe. This helps in preventing the accidental installation of malware.
Internet Explorer 7 introduced the phishing filter, which restricts access to phishing sites unless the user overrides the decision. With version 8, it also blocks access to sites known to host malware. Downloads are also checked to see if they are known to be malware-infected.
In Windows Vista, Internet Explorer by default runs in what is called Protected Mode, where the privileges of the browser itself are severely restricted—it cannot make any system-wide changes. One can optionally turn this mode off, but this is not recommended. This also effectively restricts the privileges of any add-ons.
===Security vulnerabilities===
Internet Explorer has been subjected to many security vulnerabilities and concerns such that the volume of criticism for IE is unusually high. Much of the spyware, adware, and computer viruses across the Internet are made possible by exploitable bugs and flaws in the security architecture of Internet Explorer, sometimes requiring nothing more than viewing of a malicious web page to install themselves. This is known as a "drive-by install”.
==Controversies==
WARNING: THIS SECTION COVERS SENSITIVE TOPICS, SUCH AS NOTABLE ALLEGATIONS, AS WELL AS SPOILERS. VIEWER DISCRETION IS ADVICED! 
===Criticism===
Internet Explorer has been criticized for its slow performance, outdated technology, security vulnerabilities and limited support. 
Internet Explorer has also been subjected to many security vulnerabilities and concerns such that the volume of criticism for IE is unusually high. Much of the spyware, adware, and computer viruses across the Internet are made possible by exploitable bugs and flaws in the security architecture of Internet Explorer, sometimes requiring nothing more than viewing of a malicious web page to install themselves. This is known as a "drive-by install.” There are also attempts to trick the user into installing malicious software by misrepresenting the software's true purpose in the description section of an ActiveX security alert.
The German government warned users against using Internet Explorer and recommended switching to an alternative web browser, due to the major security hole described above that was exploited in Internet Explorer. The Australian and French Government issued a similar warning a few days later.
===Removal during the United States v. Microsoft Corp. case===
While a major upgrade of Internet Explorer can be uninstalled in a traditional way if the user has saved the original application files for installation, the matter of uninstalling the version of the browser that has shipped with an operating system remains a controversial one. 
The idea of removing a stock install of Internet Explorer from a Windows system was proposed during the United States v. Microsoft Corp. case. One of Microsoft's arguments during the trial was that removing Internet Explorer from Windows may result in system instability.https://web.archive.org/web/20110115024801/http://www.wired.com/politics/law/news/1999/02/17689https://web.archive.org/web/20110115024801/http://www.wired.com/politics/law/news/1999/02/17689
===Impersonation by malware ===
The popularity of Internet Explorer led to the appearance of malware abusing its name. On January 28, 2011, a fake Internet Explorer browser calling itself "Internet Explorer – Emergency Mode" appeared. It closely resembled the real Internet Explorer but had fewer buttons and no search bar. If a user attempted to launch any other browser such as Google Chrome, Mozilla Firefox, Opera, Safari, or the real Internet Explorer, this browser would be loaded instead. It also displayed a fake error message, claiming that the computer was infected with malware and Internet Explorer had entered "Emergency Mode.” It blocked access to legitimate sites such as Google if the user tried to access them.https://web.archive.org/web/20110630065328/http://www.im-infected.com/hijacker/internet-explorer-emergency-mode.html"Bleeping Computer – Fake IE Emergency Mode (by fake AVG)" - Wired (January 15, 2011)
==See Also==
*Internet Explorer in Wikipedia.
== References==
Category:Discontinued web browsers