Microsoft Internet Explorer 5 (also knowns as 5.0 or IE5) is a graphical web browser released in March 1999 by Microsoft, primarily for Microsoft Windows, but initially with versions available for Apple Macintosh, Solaris, and HP-UX. (see Internet Explorer for Mac and Internet Explorer for Unix)

It was one of the main participants of the first Browser war. Its distribution methods and Windows integration were involved in United States v. Microsoft. It was superseded by Microsoft Internet Explorer 6.0 in August 2001, although IE 5.x remains the last version for Windows 3.1, Windows NT 3, and Windows 95. Version 5.0 was included with Windows 98 Second Edition (using the Trident II layout), and 5.5 with Windows Me (Trident III) when they were introduced.

IE5 presided over a large market share increase over Netscape Navigator between 1999 and 2001, and offered many advanced features for its day. In addition, it was compatible with largest range of OS of all the IE versions. However, support for many OS quickly dropped off with later patches, and Windows XP and later Windows versions are not supported, because of inclusion of later IE versions.

Overview

Usage share of Internet Explorer 5 rose rapidly between its release in early 1999 to being replaced by IE6 in mid 2001;Graph from 1994 to 2008Internet Explorer 5.2.3 under Mac OS X 10.5.0Internet Explorer 5 under Solaris

Version 5.0, launched on March 18, 1999, and subsequently included with Windows 98 Second Edition and bundled with Office 2000, was a significant release that supported bi-directional text, ruby characters, XML, XSL and the ability to save web pages in MHTML format. There was enhanced support for CSS Level 1 and 2. However, Internet Explorer 5 incorrectly includes the padding and borders within a specified width or height; this results in a narrower or shorter rendering of a box. An issue related to the Internet Explorer box model bug, and only more fully resolved in Internet Explorer 7.

With the release of Internet Explorer 5.0, Microsoft released the first version of XMLHttpRequest, giving birth to Ajax (although the term "Ajax" wasn't coined until years later.) XMLHttpRequest(XHR), which is an API that can be used by JavaScript, and other web browser scripting languages to transfer XML and other text data between a web page's Client-Side and Server-Side, and was available since the introduction of Internet Explorer 5.0 and is accessible via JScript, VBScript and other scripting languages supported by IE browsers. Windows Script Host was also installed with IE5, although later on Viruses and malware would attempt to use this ability as an exploit, which resulted pressure to disable it for security reasons. Smart Offline Favorites feature was added to the Active Desktop component introduced in IE4.

HTML Application (HTA) is a Microsoft Windows application written with HTML and Dynamic HTML and introduced with IE5. Internet Explorer 5.0 did not have the Favicon support though. Windows Script Host was introduced, which provides scripting capabilities comparable to batch files, but with a greater range of supported features.

The actual release of Internet Explorer 5 happened in three stages. Firstly, a Developer Preview was released in June 1998 (5.0B1), and then a Public Preview was released in November 1998 (5.0B2). Then in March 1999 the final release was released (5.0). In September it was released with Windows 98. Version 5.01, a bug fix version, was released in December 1999. Windows 2000 includes this version. Version 5.0 was the last one to be released for Windows 3.1x or Windows NT 3.x.

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 includes support for 128-bit encryption.

United States v. Microsoft

Main article: United States v. Microsoft

On April 3, 2000, Judge Jackson issued his findings of fact that Microsoft had abused its monopoly position by attempting to "dissuade Netscape from developing Navigator as a platform", that it "withheld crucial technical information", and attempted to reduce Navigator's usage share by "giving Internet Explorer away and rewarding firms that helped build its usage share" and "excluding Navigator from important distribution channels".

Jackson also released a remedy that suggested Microsoft should be broken up into two companies. This remedy was overturned on appeal, amidst charges that Jackson had revealed a bias against Microsoft in communication with reporters. The findings of fact that Microsoft had broken the law, however, were upheld. Seven months later, the Department of Justice agreed on a settlement agreement with Microsoft. As of 2004, although nineteen states have agreed to the settlement, Massachusetts is still holding out.

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