For the first time ever, fewer than 90% of computer users are running Windows. The figures show the growing success of rival operating systems -- though there's no sign of Microsoft losing its dominant position any time soon.

The figures come from Internet services firm Net Applications. They regularly measure which operating system users are using when connecting to web sites. While this is obviously not a perfect way to quantify market dominance, it does provide a decent sampling method given how many users have an Internet connection these days.

The figure for Windows in November was 89.6%, a drop of 0.84 percentage points on last month. Most of that share was lost to Mac systems which were up to 8.9%. Linux systems are at 0.83%, with the iPhone now established in fourth place with 0.37%, nearly ten times the share of the fifth place Sony Playstation.

Among Windows users, Windows XP was notably down, with Vista rising slightly. That's been a trend all year with the withdrawal of XP from most sales outlets, though the shift was notably large this month.

The trend away from Microsoft continues in figures for web browsers: Internet Explorer continues to lose share, while Mozilla's Firefox topped 20% for the first time. (Source: cnn.com)

There is one note of caution on reading too much into the exact figures: most calendar months have up to 23 work days, whereas last month there were 5 weekends in a 30 day period (yielding 16-18 working days), plus many Americans took one or two days off for Thanksgiving. Furthermore, home users are much more likely to be running Macs or experiment with alternative web browsers than those on work machines, so this does somewhat sway the figures. (Source: computerworld.com)

However, there's no denying that Windows is losing in popularity. If Microsoft is to stop this trend, they need to act now.