Internet Explorer (formerly Microsoft Internet Explorer and Windows Internet Explorer, commonly abbreviated IE or MSIE) is a deprecated series of graphical web browsers developed by Microsoft and included in 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. 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. New feature development for the browser was discontinued in 2016 in favor of new browser Microsoft Edge. Since Internet Explorer is a Windows component and is included in long-term lifecycle versions of Windows such as Windows Server 2019, it will continue to receive security updates until at least 2029. Microsoft 365 ended support for Internet Explorer on August 17, 2021, and Microsoft Teams ended support for IE on November 30, 2020. Internet Explorer will be discontinued on June 15, 2022, after which, the alternative will be Microsoft Edge with IE mode for legacy sites.
|Original author(s)||Thomas Reardon|
|Initial release||August 16, 1995|
|Operating system||Windows (and previously supported: Mac OS X, Solaris, HP-UX)|
|Platform||IA-32, x86-64, ARMv7, IA-64 (and previously supported: MIPS, Alpha, PowerPC, 68k, SPARC, PA-RISC)|
|Standard(s)||HTML5, CSS3, WOFF, SVG, RSS, Atom, JPEG XR|
|Available in||95 languages|
|License||Proprietary, requires a Windows license|
Internet Explorer was once the most widely used web browser, attaining a peak of about 95% usage share by 2003. This came after Microsoft used bundling to win the first browser war against Netscape, which was the dominant browser in the 1990s. Its usage share has since declined with the launch of Firefox (2004) and Google Chrome (2008), and with the growing popularity of mobile operating systems such as Android and iOS that do not support Internet Explorer.
Estimates for Internet Explorer's market share in 2021 are about 0.57% across all platforms, or by StatCounter's numbers ranked 9th. On traditional PCs, the only platform on which it has ever had significant share, it is ranked 6th at 1.32%, after Opera. Microsoft Edge, IE's successor, first overtook Internet Explorer in terms of market share in November 2019.
Versions of Internet Explorer for other operating systems have also been produced, including an Xbox 360 version called Internet Explorer for Xbox and for platforms Microsoft no longer supports: Internet Explorer for Mac and Internet Explorer for UNIX (Solaris and HP-UX), and an embedded OEM version called Pocket Internet Explorer, later rebranded Internet Explorer Mobile made for Windows CE, Windows Phone, and, previously, based on Internet Explorer 7, for Windows Phone 7.
On March 17, 2015, Microsoft announced that Microsoft Edge would replace Internet Explorer as the default browser on "for certain versions of Windows 10". This makes Internet Explorer 11 the last release. Internet Explorer, however, remains on Windows 10 LTSC and Windows Server 2019 primarily for enterprise purposes. Since January 12, 2016, only Internet Explorer 11 has official support for consumers; extended support for Internet Explorer 10 ended on January 31, 2020. Support varies based on the operating system's technical capabilities and its support life cycle. On May 20, 2021, it was announced that full support for Internet Explorer would be discontinued on June 15, 2022, after which, the alternative will be Microsoft Edge with IE mode for legacy sites. Microsoft is committed to support Internet Explorer that way to 2029 at least, with one years notice before it discontinued. The IE mode "uses the Trident MSHTML engine", i.e. the rendering code of Internet Explorer.
The browser has been scrutinized throughout its development for use of third-party technology (such as the source code of Spyglass Mosaic, used without royalty in early versions) and security and privacy vulnerabilities, and the United States and the European Union have alleged that integration of Internet Explorer with Windows has been to the detriment of fair browser competition.