Backward thinking

Peel the skin of any major site, from Amazon to Microsoft.com, from Sony to ZDNet. Examine their tortuous non-standard markup, their proprietary ActiveX and JavaScript (often including broken detection scripts), and ill-conceived use of Cascading Style Sheets - when they use CSS at all. It's a wonder such sites work in any browser.

They work in yesterday's mainstream browsers because the first four to five generations of Netscape Navigator and Microsoft Internet Explorer did not merely tolerate non-standard markup and browser-specific code; they actually encouraged sloppy authoring and proprietary scripting in an ill-conceived battle to own the browser space.

9.9% of Websites Are Obsolete - An excerpt from Forward Compatibility: Designing & Building With Standards, By Jeffrey Zeldman