The beginning of Internet Explorer (IE) eclipses any wide-spread use of web standards. When IE was first developed, there was a mess. Different browsers supported different tags, which meant that, when an individual or company developed a web site, it was often designed for one browser, and wouldn't display properly in another. During this period, a lot of pages had buttons or images saying "Best displayed in Netscape" or "Best viewed in Microsoft IE", ect.
Tim Berners-Lee, the creator of the World Wide Web, seeing the problem with web pages compatable with only one browser, helped found the W3C, the World Wide Web Consortium in 1994(W3C). Microsoft is a member of the W3C organization(W3C), but has not upheld the W3C's mission of "One Web". Microsoft, through the bundling of their browser with the Windows Operating System, as well as the omission of key web standards, supplemented by the implementation of proprietary standards, has been, in this position, a hypocrite at best.
Internet Explorer, even the very latest release (Version 8) has no support for SVG, a web technology that allows vector images, which can be resized without loosing clarity, to be displayed on a web page. SVG images also have the potential to be smaller than equivilant raster, or traditional, non-scalable images, thus helping to make web pages load faster, a definite advantage to anyone who has a slow internet connection.
The newest version in development, Version 9, does not support Nearly as much of HTML5 as Safari, Firefox, Chrome, or Opera.
To top it off, Internet Explorer, even in its latest implementation (Version 8) has no real support for XHTML, a key future web technology. To date, the only way an XHTML web page can be displayed at all, is to send, with that web page, an invalid content type header. In other words, if a web developer correctly describes the content of an XHTML document to a web server, Internet Explorer will not know what to do with the web page, and will ask you to download the web page!
Internet Explorer has certain scripting features built-in that enable it to interact very freely with Windows. This is dangerous. This technology, called Active-X, is a huge security risk, because it enables Active-X embedded programs to interact with Windows in ways that can allow malicious changes to a person's computer. "The ActiveX controls in Microsoft Internet Explorer, as well as Internet Explorer's popularity, make this browser the least secure option available"(Consumer Search)
Other browsers, such as Firefox and Opera, enable the user to zoom in on text, even when the website has been designed with a specific fixed size font. Internet Explorer can only zoom in on text when a website is designed with a relative-sized font. Few websites are designed with relative-sized fonts, putting readability out of reach for many people with poor eyesight.
When Tim Berners-Lee invented the World Wide Web, he invisioned it as a universal way to convey information. Web sites that only work in Internet Explorer should be considered as outdated as if they were designed before the advent of the W3C, 25 years ago.
Internet Explorer has many features that are similar to existing standards, but require a different way of doing things. What this amounts to is a waste of everybody's time.