The year is 2009. YouTube, four years old, has become the Web’s leading video site. Though Internet Explorer 6 was far from current—it had been superseded by versions 7 and 8—it nonetheless made up some 18 percent of YouTube’s traffic. These were, after all, the dark days of Windows XP; corporations had overwhelmingly stuck with Windows XP in spite of the release of Windows Vista, and Windows 7 was still some months from release. Many organizations still running XP appeared to be wishing for a kind of computational stasis: they wanted to be able to run Windows XP and Internet Explorer 6 forever, unchanging, which would greatly simplify their maintenance and support costs.
But Internet Explorer 6 was nearly eight years old and seriously showing its age. On its release, the browser had a legitimate claim to be the best, fastest, most standards compliant, and most