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Internet Explorer

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Windows Internet Explorer
Developer(s)Microsoft
Initial releaseAugust 1995
Stable release
7.0.6001.16659 (Windows Server 2008 RC0) / 2007
Operating systemMicrosoft Windows
Mac OS X (up to version 5.2.3, discontinued)
Mac OS (up to version 5.1, discontinued)
Solaris and HP-UX (up to version 5.0)
TypeWeb browser and RSS Reader
LicenseProprietary EULA
Websitemicrosoft.com/ie

Windows Internet Explorer (formerly Microsoft Internet Explorer abbreviated MSIE), commonly abbreviated to IE, is a series of proprietary graphical web browsers developed by Microsoft and included as part of the Microsoft Windows line of operating systems starting in 1995.

After the first release for Windows 95, additional versions of Internet Explorer were developed for other operating systems: Internet Explorer for Mac and Internet Explorer for UNIX (the latter for use through the X Window System on Solaris and HP-UX). Only the Windows version remains in active development; the Mac OS X version is no longer supported.

It has been the most widely used web browser since 1999, peaking at nearly 90% market share with IE6 in the early 2000s—corresponding to over 900 million users worldwide by 2006.[1][2]

Though released in 1995 as part of the initial OEM release of Windows 95, Internet Explorer was not included in the first retail, or shrink-wrap, release of Windows 95. The most recent release is version 7.0, which is available as a free update for Windows XP with Service Pack 2, and Windows Server 2003 with Service Pack 1 or later, and is included with Windows Vista. Versions of Internet Explorer prior to 6.0 SP2 are also available as a separate download for versions of Windows prior to Windows XP. An embedded OEM version called Internet Explorer for Windows CE (IE CE) is also available for WinCE based platforms and is currently based on IE6. Another Windows CE/ Windows Mobile browser known as Internet Explorer Mobile is from a different codebase and should not be confused with desktop versions of the browser.

Version history

Internet Explorer began conceptually as one of the major components of the unreleased Windows 97, imagined as the successor to Windows 95. The project was started in the summer of 1994 by Thomas Reardon and subsequently led by Benjamin Slivka, leveraging source code from Spyglass, Inc. Mosaic, an early commercial web browser with formal ties to the pioneering NCSA Mosaic browser. In late 1994, Microsoft licensed Spyglass Mosaic for a quarterly fee plus a percentage of Microsoft's non-Windows revenues for the software. Although bearing a name similar to NCSA Mosaic, which was the first widely used web browser, Spyglass Mosaic was relatively unknown in its day and used the NCSA Mosaic source code only sparingly.[3]


Versions 1, 2, and 3

Browser Market Share in September 2007[4]
Internet Explorer, All Versions 77.86%
Internet Explorer 4 0.01%
Internet Explorer 5.0 0.17%
Internet Explorer 5.5 0.16%
Internet Explorer 6 42.75%
Internet Explorer 7 34.60%
File:Internet Explorer 1.0 and 2.0 logo.png
Internet Explorer's original logo

Internet Explorer was not widely used until the release of version 3, which was the first version developed without Spyglass source code (although still using Spyglass "technology", so the Spyglass licensing information remained in the program's documentation). Internet Explorer 3 was the first major browser with CSS support, although this support was only partial. Released on August 13 1996, it also introduced support for ActiveX controls, Java applets, inline multimedia, and the PICS system for content metadata. These were significant improvements compared to its main competitor at the time, Netscape Navigator. Version 3 also came bundled with Internet Mail and News, NetMeeting, and an early version of the Windows Address Book, and was itself included with Windows 95 OSR 2. Version 3 proved to be the first popular version of Internet Explorer, which brought with it increased scrutiny. In the months following its release, a number of security and privacy vulnerabilities were found by researchers and hackers.


Version 4

Main Wikipedia page using Internet Explorer 4.0

Version 4, released in September 1997, deepened the level of integration between the web browser and the underlying operating system. Installing version 4 on a Windows 95 or Windows NT 4 machine and choosing "Windows Desktop Update" would result in the traditional Windows Explorer being replaced by a version more akin to a web browser interface, as well as the Windows desktop itself being web-enabled via Active Desktop. The integration with Windows, however, was subject to numerous packaging criticisms (see United States v. Microsoft). This option was no longer available with the installers for later versions of Internet Explorer but was not removed from the system if already installed. Internet Explorer 4 introduced support for Group Policy, allowing companies to configure and lock down many aspects of the browser's configuration. Internet Mail and News was replaced with Outlook Express, and Microsoft Chat and an improved NetMeeting were also included. This version also was included with Windows 98.


Version 5

File:Internet Explorer 5.png
Main Wikipedia page using Internet Explorer 5.0

Version 5, launched on March 18, 1999, and subsequently included with Windows 98 Second Edition and bundled with Office 2000, was another significant release that supported bi-directional text, ruby characters, XML, XSL and the ability to save web pages in MHTML format. (Windows 2000 included Internet Explorer 5.01 instead.)

Also, with the release of Internet Explorer 5.0, Microsoft released the first version of XMLHttpRequest, giving birth to Ajax (even though the term "Ajax" wasn't coined until years later.)

Version 5.5 followed in July 2000, improving its print preview capabilities, CSS and HTML standards support, and developer APIs; this version was bundled with Windows Me. Version 5.5 also included support for 128-bit encryption.


Version 6

Main Wikipedia page using Internet Explorer 6.0

Version 6 was released on August 27, 2001, a few weeks before Windows XP. This version included DHTML enhancements, content restricted inline frames, and partial support of CSS level 1, DOM level 1 and SMIL 2.0.[5] The MSXML engine was also updated to version 3.0. Other new features included a new version of the Internet Explorer Administration Kit (IEAK), Media bar, Windows Messenger integration, fault collection, automatic image resizing, P3P, and a new look-and-feel that was in line with the "Luna" visual style of Windows XP. In 2002, the Gopher protocol was disabled and support for it was dropped in Internet Explorer 7.[6]


Version 7

File:IE7XP.png
Wikipedia main page using Internet Explorer 7.0
File:IE7 Vista Ultimate.png
A sreenshot of IE7 using Windows Vista in fullscreen.

On February 15, 2005, Microsoft Chairman Bill Gates announced that the new version of its browser would be released at the RSA Conference 2005 in San Francisco.[7] Internet Explorer 7 is available only for Windows XP SP2 and later, including Windows Server 2003 SP1 and Windows Vista. Sometime in October 2006, prior to the launch of IE7, Yahoo provided a post-beta version of Internet Explorer 7 bundled with a new version of Yahoo Messenger. The first beta version of the browser was released on July 27, 2005 for technical testing, and a first public preview version of Internet Explorer 7 (Beta 2 preview: Pre-Beta 2 version) was released on January 31, 2006. The final public version was released on October 18 2006. Version 7 is intended to defend users from phishing as well as deceptive or malicious software, and it also features full user control of ActiveX and better security framework, including not being integrated as much with Windows[8] as previous versions, thereby increasing security. Unlike previous versions, the Internet Explorer ActiveX control is not hosted in the Windows Explorer process, but rather it runs in it own process. It also includes bug fixes, enhancements to its support for web standards, tabbed browsing with tab preview and management, a multiple-engine search box, a web feeds reader, Internationalized Domain Name support (IDN), and antiphishing filter. On October 5, 2007, Microsoft removed the 'genuine software' validation before install, which meant that all versions of Windows, whether legitimate or not, are able to install the browser.

Version 8

Template:Future software Version 8 of Internet Explorer is in development as written by Chris Wilson on the IEBlog.[9][10] From the blog and based on the conferences of MIX 2007; RSS, CSS, AJAX, microformats, more options for user interface customization and improved web development tools are possibilities for inclusion into the forthcoming version of Internet Explorer, with security still being the top priority.[11] Support for more of the CSS 2.1 specification as well as changes to the DOM for interoperability with other web browsers is in the cards.

Features

File:Internet Explorer 7 pop-up blocked.png
Internet Explorer 7's pop-up blocker.

Internet Explorer has been designed to view the broadest range of web pages and to provide certain features within the operating system, including Microsoft Update. During the heyday of the historic browser wars, Internet Explorer superseded Netscape by supporting many of the progressive features of the time[citation needed].

Component architecture

The Component Object Model (COM) technology is used extensively in Internet Explorer. It allows third parties to add functionality via Browser Helper Objects (BHO); and allows websites to offer rich content via ActiveX. As these objects can have the same privileges as the browser itself (in certain situations), there is a concern over security. Recent versions of Internet Explorer provide an Add-on Manager for controlling ActiveX controls and Browser Helper Objects and a "No Add-Ons" version (Under Programs/Accessories/System Tools).

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 that of Windows Explorer (although this feature requires a shell window to be opened in recent versions of the browser, rather than natively within the browser). Visual Basic for Applications (VBA) is not supported, but available via extension (iMacros).

Recent versions feature pop-up blocking and tabbed browsing. Tabbed browsing can also be added to older versions by installing Microsoft's MSN Search Toolbar.

Security framework

Internet Explorer uses a zone-based security framework, which means that sites are grouped based upon certain conditions. It allows the restriction of broad areas of functionality, and also allows specific functions to be restricted.

Patches and updates to the browser are released periodically and made available through the Windows Update service, as well as through Automatic Updates. Although security patches continue to be released for a range of platforms, most recent feature additions and security improvements are released for Windows XP only.

Recent versions of Internet Explorer provide Download Monitoring and Install Monitoring allowing users the choice of whether or not to download and install executables, in two stages. This helps to prevent installation of malware. Executable files downloaded using Internet Explorer are marked by the operating system as being potentially unsafe, and will prompt the user to confirm they want to run the executable every time, until the user confirms the file is "safe".

Group Policy

Internet Explorer is fully configurable using Group Policy. Administrators of Windows Server domains can apply and enforce a variety of settings 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 on a per-user and per-machine basis.

Standards support

Internet Explorer, using the Trident layout engine, almost fully supports HTML 4.01, CSS Level 1, XML 1.0 and DOM Level 1, with minor implementation gaps. It partially supports CSS Level 2 and DOM Level 2, with some implementation gaps and conformance issues. XML support brings with it support for XHTML, however Microsoft has buried this support since IE 5.0 making it difficult to access. Like other browsers it can consume XHTML when served as MIME type “text/html”. It can also consume XHTML as XML when served as MIME types “application/xml” and “text/xml”, however this requires a small XSLT measure[12] to re-enable the XHTML as XML support. It pretends to not comprehend XHTML when vended in the preferred type as “application/xhtml+xml” and instead treats it as an unfamiliar file type for download.

Internet Explorer uses DOCTYPE sniffing to choose between "quirks mode" (renders similarly to older versions of MSIE) and standards mode (renders closer to W3C's specifications) for HTML and CSS rendering on screen (for printing Internet Explorer always uses standards mode). It fully supports XSLT 1.0 or the December 1998 Working Draft of XSL, depending on the version of MSXML (a dynamic link library) available. It also provides its own dialect of ECMAScript called JScript.

Software extensions

Since 2006, Microsoft has released many purchasable and freeware extensions for Internet Explorer.

Criticism

Security

Much criticism of Internet Explorer is related to concerns about security: 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 in order to install themselves. This is known as a "drive-by download": an attempt to trick the user into installing malicious software by misrepresenting the software's true purpose in the description section of an ActiveX security alert.

While Internet Explorer is not alone in having exploitable vulnerabilities, its ubiquity has resulted in many more affected computers when vulnerabilities are found. Microsoft has not responded as quickly as competitors in fixing security holes and making patches available,[13] in some cases giving malicious web site operators months to exploit them before Microsoft releases a patch.

The security website Secunia keeps an up-to-date list of known unpatched vulnerabilities. According to the Washington Post, Internet Explorer was known to have exploit code for unpatched critical flaws for 284 days of 2006 [1]. The article goes on to compare this with 9 days for Mozilla Firefox.

Standards support

Other criticisms concern Internet Explorer's support of open standards, because the browser often uses proprietary extensions to achieve similar functionality.[citation needed] In addition, although Internet Explorer 7 is significantly more compliant than previous versions, it remains the least standards-compliant of any major browser.[14]

Internet Explorer supports, to some degree, a number of standardized technologies, but has numerous implementation gaps and conformance failures[citation needed]—some minor, some not—that have led to criticism from an increasing number of developers.[citation needed] The increase is attributable, in large part, to the fact that competing browsers that offer relatively thorough, standards-compliant implementations are becoming more widely used.[citation needed]

It is also claimed that lack of support in Internet Explorer is responsible for holding back the widespread adoption by webmasters of several new open technology standards (for example, PNG, which has been supported by many browsers since 1996, and yet was not completely supported in Internet Explorer until version 7, and also SVG, supported elsewhere in 2001, and as of yet unsupported in Internet Explorer without a 3rd party plugin).

Internet Explorer's ubiquity, in spite of its technical inferiority in this area[citation needed], frustrates developers who want to write standards-compliant, cross-browser code and the advanced functionality it provides [citation needed], because they are often stuck coding pages around Internet Explorer's bugs, proprietary featureset, and missing standards support instead.[citation needed]

Web developers must work with the technology supported across all browsers for cross-platform development, and Internet Explorer is often criticized for being technically inferior.[citation needed] These include supporting fewer or wrongly interpreting more CSS, HTML, and DOM features than Firefox or Opera and not having native XHTML support.[15] As a result of these, it does not pass the Acid2 test, a test case designed by the Web Standards Project to verify CSS compliance.

Market adoption

Usage share

Usage share of Internet Explorer, 1994–2007[16]

The adoption rate of Internet Explorer seems to be closely related to that of Microsoft Windows, as it is the default web browser that comes with Windows. Since the integration of Internet Explorer 2.0 with Windows 95 OSR 1 in 1996, and especially after version 4.0's release, the adoption was greatly accelerated: from below 20% in 1996 to about 40% in 1998 and over 80% in 2000. This effect, however, has recently been dubbed the "Microsoft monoculture", by analogy to the problems associated with lack of biodiversity in an ecosystem. By 2002, Internet Explorer had almost completely superseded its main rival Netscape and dominated the market.

After having fought and won the browser wars of the late 1990s, Internet Explorer began to see its usage share shrink. Having attained a peak of about 95% during 2002 and 2003, it has since been in a slow, steady decline, due to the adoption of Mozilla Firefox, which statistics indicate is currently the most significant competition. Nevertheless, Internet Explorer remains the dominant web browser, with a global usage share of around 83% (based on statistics reference). Usage is higher in Asia and lower in Europe. For example, the share is around 94% in Japan,[17] and around 56% in Germany.[18]

Industry adoption

The proprietary extension mechanism ActiveX is used by many public websites and web applications, including eBay. Similarly, Browser Helper Objects are also used by many search engine companies and third parties for creating add-ons that access their services, for example, search engine toolbars. Because of the use of COM, it is possible to embed web-browsing functionality in third-party applications. Hence, there are a number of Internet Explorer shells, and a number of content-centric applications like RealPlayer also use Internet Explorer's web browsing module for viewing web pages within the applications.

Some exhibits used by theme parks and other venues involving "activities" use Internet Explorer. For instance, the interactive video games at an exhibit in Epcot in Bay Lake, Florida use Internet Explorer [2].

OS compatibility

File:IE6ubuntu.png
Internet Explorer 6 in Ubuntu running under Wine.

IE versions, over time, have had widely varying OS compatibility, ranging from being available for many platforms and several versions of Windows to just a couple versions of Windows. Many versions of IE had some support for an older OS but stopped getting updates. The increased growth of the Internet in the 1990s and 2000s means that current browsers with small market shares have more total users than the entire market early on. For example, 90% market share in 1997 would be roughly 60 million[19] users, but by the start of 2007 90% market share would equate to over 900 million users.[20] The result is that later versions of IE6 had many more users in total than all the early versions put together. The release of IE7 at the end of 2006 resulted in a collapse of IE6 market share; by February 2007 market version share statistics showed IE6 at about 50% and IE7 at 29%.[21] Regardless of the actual market share, the most compatible version (across operating systems) of IE was 5.x, which had Mac, Unix, and most versions of Windows available and supported for a short period in the late 1990s. By 2007, IE had much narrower OS support, with the latest versions supporting only Windows XP Service Pack 2 and above.

Browser Years Rendering engine Windows IBM OS/2 Mac OS X (Intel/PPC) Mac OS 9 Mac OS 8 System 7 (PPC/68k) Unix (HP-UX, Solaris)
Vista XP 2000 98/Me NT 4.0 95 3.1
OS release years - - 2006 2001 2000 1998/2000 1996 1995 1992 1988 2001 1999 1997 1991 (1990s)
IE 7 2006 (Trident V) Included Yes

(SP2 Only)

No No No No No No No No No No No
IE 6 2001-2004 (Trident IV) No Included (6.0 SP2)* Yes

(6.0 SP1)

Dropped (6.0 SP1) Dropped (6.0 SP1) No No No No No No No No
IE 5.5 1998-2000 Trident III No No Included (5.01) Included (4.01/5.5 SP2) Yes Included** No No No No No No No
IE 5.0 1998-2000 Trident II (5.0 for Win),Trident III (5.5 for Win),Tasman v0.x (Mac) No No Included (5.01) Included (4.01/5.5 SP2) Yes Included** Yes No Dropped (5.2.3) Included Dropped (5.2.3) Included Dropped (5.1.7) Dropped (5.1.7) Dropped * (5.01 SP1)
IE 4.0 1997-1998 Trident
IE 3.0 1996-1997 Trident IV No No No Yes Included Included** Yes Windows 3.1 version No Yes Included Yes Yes *
IE 2.0 1995 Unknown No No No Yes Included (2.0) Included** Yes Windows 3.1 version No Un­known Un­known Beta (2.0) No
IE 1.0 1995 Unknown No No No Yes Yes Yes Yes Windows 3.1 version No No No No No

[22][23]

* Internet Explorer 6 SP2 is only available as part of a standalone Windows XP SP2.
** The version of Internet Explorer included with Windows 95 varied by OSR release; 2.0 was included with OSR1, 3.0 was included with OSR2, and 4.0 was included with OSR2.5.

"Standalone" Internet Explorer

While Microsoft claims it is impossible to keep multiple versions of Internet Explorer on the same machine, some hackers have successfully separated several versions of Internet Explorer, making them standalone applications. These are referred to as "standalone" IEs and have included versions 3 through 7.

Microsoft has discontinued standalone installers for Internet Explorer to the general public. However, there are unofficial procedures for downloading the complete install package. Internet Explorer standalone hacks exploit a known workaround to DLL hell, which was introduced in Windows 2000, called DLL redirection.

It is also possible to install Internet Explorer on operating systems supporting WINE.

  • IEs4Linux automatically sets up Internet Explorer 5.0, 5.5, and 6.0 in WINE. Supporting Internet Explorer 7 is currently in development; as of August 2007, the IE7 rendering engine can be used with the IE6 UI.[24]

Removal

While a major upgrade of Internet Explorer can be uninstalled in a traditional way if the user has saved the original application files for uninstallation, 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 first proposed during the United States v. Microsoft case. Critics felt that users should have the right to uninstall Internet Explorer freely just like any other application software. One of Microsoft's arguments during the trial was that removing Internet Explorer from Windows may result in system instability.

The Australian computer scientist Shane Brooks demonstrated that Windows 98 could in fact run with Internet Explorer removed.[25] Brooks went on to develop software designed to customize Windows versions by removing "undesired components", which is known as 98lite. He later created XPLite to support NT based operating systems. Both of these pieces of software can remove IE after the installation of the operating system. However, both of these pieces of software work, in part, by installing obsolete versions of components (such as Windows Explorer) required by the operating system to function.

There are a few popular methods for removing IE from a copy of the Windows install disc so it never touches the user's hard drive. A method developed by Fred Vorck involves the manual removal of IE from installation discs. nLite, on the other hand, is an automated program that allows users to exclude IE and many other Windows components from installation as desired. In some older versions of Windows and in Windows Fundamentals there is an option to install Internet Explorer.

Removing Internet Explorer does have a number of consequences. Some applications that depend on libraries installed by IE may fail to function, or have unexpected behaviors. Intuit's Quicken is a typical example, which depends heavily upon the HTML rendering components installed by the browser. The Windows help and support system will also not function due to the heavy reliance on HTML help files and components of IE. It is also not possible to run Microsoft's Windows Update with any other browser due to the service's implementation of an ActiveX control, which no other browser supports.

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See also

  1. ^ "History and Growth of the Internet". Retrieved 2007-03-03.
  2. ^ "Market share for browsers, OSs, and search engines". Retrieved 2007-03-03.
  3. ^ Eric Sink (2005-05-12). "Memoirs From the Browser Wars". Retrieved 2006-03-24.{{cite web}}: CS1 maint: year (link)
  4. ^ Browser Market Share September 2007
  5. ^ "SMIL Standards and Microsoft Internet Explorer 6, 7, and 8". Retrieved 2007-05-27.
  6. ^ "Using a web browser to access gopher space". Retrieved 2007-05-11.
  7. ^ Gates Highlights Progress on Security, Outlines Next Steps for Continued Innovation, May 12 2005.
  8. ^ Article regarding Internet Explorer 7's integration into windows, March 24 2006
  9. ^ Chris Wilson (2007-04-19). "What to Expect from IE at MIX07?". Retrieved 2007-05-02.{{cite web}}: CS1 maint: year (link)
  10. ^ Jeremy Reimer (2007-05-02). "Microsoft drops hints about Internet Explorer 8". Retrieved 2007-05-02.{{cite web}}: CS1 maint: year (link)
  11. ^ "Microsoft hints at general plan for IE 8". Retrieved 2007-05-11.
  12. ^ see small XSLT measure Anne’s Weblog] for a sample of the minimal transformation required.
  13. ^ Firefox Sports More Bugs, But IE Takes 9 Times Longer To Patch, TechWeb.
  14. ^ Web browser standards support summary. Web Devout.
  15. ^ Web browser standards support summary. Web Devout.
  16. ^ Usage share of web browsers
  17. ^ Firefox's Market Share Nears 7 Percent, WebSideStory
  18. ^ Global usage share Mozilla Firefox has increased, OneStat
  19. ^ "History and Growth of the Internet". Retrieved 2007-03-03.
  20. ^ "History and Growth of the Internet". Retrieved 2007-03-03.
  21. ^ "Market share for browsers, operating systems and search engines". Retrieved 2007-03-03.
  22. ^ "Internet Explorer for Macintosh or Windows 3.1". Retrieved 2007-03-01.
  23. ^ "Download Netscape 4.7x & 4.8". Retrieved 2007-03-01.
  24. ^ http://www.tatanka.com.br/ies4linux/page/Beta
  25. ^ "U.S. v. Microsoft: Court's Findings of Fact". United States Department of Justice. 2005-11-05. Retrieved 2005-05-12.{{cite web}}: CS1 maint: year (link).