Though perhaps painful to acknowledge, Windows XP and Vista are still operating systems of choice for the vast majority of consumers. Ironically, open source applications may be helping to sustain that monopoly-like status. And what operating systems have the most open source software to choose from? Windows XP and Vista. It's a vicious cycle that developers are caught in?they have to develop for the platform with the most users to encourage the best growth for their applications. But, at the same time, they're frustrated by clumsiness in the way Windows Vista in particular was designed. Linux provides a welcoming alternative, but lacks the number of users necessary to truly reach critical mass and break through to the masses.