It may seem odd, or self-defeating that Microsoft would invest so much effort developing a next generation Web browser that isn't compatible with Windows XP. The legacy Windows OS still enjoys greater than 50 percent market share--more than Windows 7 and Windows Vista combined. But, Microsoft sees the writing on the wall, and there is a key message with IE9: the operating system and hardware matter as much as the browser itself.
Microsoft could have developed a browser that was an incremental improvement over Internet Explorer 8 just for the sake of developing a new browser, and it could have maintained backward compatibility with Windows XP. However, doing so would greatly restrict what Microsoft is able to accomplish with that browser. At some point you have to cut the cord and move on to embrace the future rather than continuously coddling the past.
The line in the sand drawn by Internet Explorer 9 reminds me of the issues my kids face when it comes to PC gaming. All three of my boys are more or less addicted to Minecraft. Although the graphics make Pitfall on an Atari 2600 look advanced, the engine that drives the Minecraft world, and the sheer size of the virtual Minecraft world make it a demanding game on system resources.
My younger son can play it, but he is forced to disable many of the advanced rendering and graphics options, and still experiences significant lag. When he is playing alone, it doesn't really matter, but when playing online with others the lag can seriously impact gameplay. My older boys have new quad-core PCs with high-end graphics cards and can turn on every maxed out graphics option available and still get seamless, blazing speed from the game.
Minecraft can be played on both the older, legacy hardware, as well as on newer, more powerful hardware, but the game experience is defined by the capabilities of the hardware. That is where Microsoft has taken the browser with Internet Explorer 9--the underlying hardware platform and capabilities of the operating system are critical elements of the Web experience.
With Internet Explorer 9, the browser becomes a tightly integrated component of the operating system, and websites become applications that extend the desktop experience to the Web. In order to deliver adequate performance and provide the functionality Microsoft delivers with IE9, you have to have a solid operating system and hardware foundation.
Yes, Microsoft may alienate customers by not providing backwards compatibility with Windows XP. But, when those customers move to Windows 7--or eventually Windows 8--they will appreciate that Microsoft had the conviction to abandon backward compatibility in favor of a more immersive and integrated Web experience.
