Thanks to corporate use and ties to Windows, Internet Explorer has remained dominant in the browser space ever since it won the first browser wars with Netscape a decade ago.
However, by allowing the browser to stagnate after the release of Windows XP in 2001, Microsoft created an opening that paved the way for the rise of Firefox and, more recently, Google's Chrome.
As a result Internet Explorer celebrates its 15th birthday Monday as market leader and like an upstart trying to compete against powerful rivals.
IE through the years
As Microsoft's browser turns 15, a look back at how it's evolved.
1995: Internet Explorer 1.0
The first version of IE came in August 1996, a month after Microsoft released Windows 95. The browser was not part of the operating system, but instead was included as part of an "Internet Jumpstart Kit" in the Microsoft Plus add-in.
1995: Internet Explorer 2.0
In November 1995, Microsoft released Internet Explorer 2.0, its first browser to offer both Macintosh and Windows support. IE 2.0 also added support for the Secure Socket Layer (SSL) protocol, HTTP cookies, and Internet newsgroups.
1996: Internet Explorer 3.0
Released in August 1996, IE3 included support for e-mail, the display of GIF and JPG files, and direct playback of streaming audio without the need for additional applications.
1997: Internet Explorer 4.0
IE4 added support for Dynamic HTML (DHTML), which allowed for interactive Web sites where menus could be expanded or images could be moved around. IE4 also brought the arrival of Microsoft Outlook Express 4, an improvement to the mail and newsgroup readers that had been part of IE.
1998: Internet Explorer 5.0
Released in September 1998, IE5 expanded on the support for DHTML and allowed for greater personalization.
2001: Internet Explorer 6
Released as part of Windows XP, Internet Explorer 6 became the standard in Web browsing for years, eventually to the dismay of the entire industry, including Microsoft itself, which has struggled to move customers to more modern and secure versions of its browser.
2009: Internet Explorer 8
Released in March 2009, Internet Explorer 8 was an attempt by Microsoft to modernize its underlying browsing engine. Other features included support for creating small "Web clips" of a portion of a Web site as well as the use of "accelerators" to take action on a highlighted piece of text. A version of IE8 was also built in as part of Windows 7.
2011?: Internet Explorer 9
Source: Microsoft and CNET
Arguably, the browser has never been more important--or competitive. As of July, Microsoft had just over 60 percent of the market, gaining share for two months in a row after years of ceding ground to Firefox and Chrome. Firefox, meanwhile, held about 23 percent, Chrome about 7 percent, and Apple's Safari roughly 5 percent, according to Net Applications.
Google is trying to make the case that not only does it have the best browser in Chrome, but further that the browser--and the Web-based services it connects to--have grown so capable that basic PCs basically need nothing else. That argument will be turned into a product later this year when the first Chrome OS-based Netbooks are scheduled to hit the market.
For its part, Microsoft is counting on an improved Internet Explorer to help its argument that the PC and Windows still matter. With Internet Explorer 9, the company is trying to both reassert itself in the browser wars and show the power of the PC by expanding the browser to tap the graphics power inherent in modern computers.
Redmond has already released a few technical previews of IE9 and is working on a beta version of IE9, set to be released September 15. The company hasn't said when to expect a final version of the browser, but it appears unlikely to happen in 2010. Next spring's Mix trade show seems a reasonable target.
While Microsoft works on the next version of IE, here at CNET we decided to take a look back at Redmond's sometimes troubled history with its browser. What started as a me-too competitor to Netscape's browser at the beginning of the dot-com boom quickly became the main point of contention in Microsoft's antitrust battles with U.S. and European regulators.
At the heart of those fights was a simple question still being asked in computing: Is the operating system or the browser more important? At Microsoft, the answer split the difference: The browser should be part of the operating system. And that's where the trouble began.
Internet Explorer made its debut on August 16, 1995, just one month after Microsoft released Windows 95. The browser was part of something called the Internet Jumpstart Kit that was part of the Microsoft Plus add-on to Windows 95.
The browser's origins can be traced to the company's big Internet Strategy Day in which Microsoft announced it had recognized the Internet and would be adding Net capabilities to all of its products. Microsoft got much of the code by licensing the Mosaic browser from Spyglass.
Internet Explorer didn't immediately oust Netscape from the market, with Redmond's rival managing to hold on to more than half of the market through 1997.
A key move for Microsoft came with IE 3.0, which Microsoft included in the operating system--a move that led to significant antitrust scrutiny for Microsoft starting in 1996 and continuing until as recently as last year when Microsoft was told by the European Union that the inclusion of a browser in Windows appeared to violate its laws.
Redmond threatened to pull the browser out of Windows entirely in Europe--a move that would have not only made it hard to use IE--but also to download any other browser. However, the company relented and instead has agreed to use a "ballot screen" in Europe that lets PC buyers or those upgrading Windows choose which browser or browsers they want to install.
Elsewhere, IE remains an integrated part of Windows, though there are options that allow most of its features to be hidden.
Despite its popularity, IE has drawn much scorn from developers and users, particularly the venerable IE6 browser that shipped as part of Windows XP. Even Microsoft itself has been trying to get users off of IE6, but its long life (and that of XP) means that it has remained despite the ire.
The modern browser wars
After winning the first battle against Netscape, Microsoft settled into a slow pace of small evolutions with the browser that tended to come only as Redmond updated Windows itself.
IE6 got a significant security update along with Windows XP with Service Pack 2. However, because Microsoft didn't have a major release of Windows from 2001 until Vista in 2006, IE failed to keep pace on the innovation front, while Firefox continued to add features such as tabbed browsing.
Microsoft caught up a little bit on the features front with IE7 and with IE8, which debuted last year, the company aimed to make up some ground on the standards front.
However, IE9, still in development, is the company's big bet on offering a browser that can compete technically with browsers from Google, Mozilla, and Apple.
Microsoft hasn't said much about how the browser will look, but it has hinted that it aims for a more minimalistic approach.
"The browser is the theater," Microsoft's Ryan Gavin said in an interview last week. "We're not the play. You don't want the theater to block the view."