IE's share slipped very slightly from 52.98% in January to 52.84% in February, according to NetMarketShare. StatCounter thinks it is faring worse, going from 37.45% to 35.75%. IE stands to be overtaken by Chrome if the trends reported by StatCounter continue.
Chrome has recorded steady growth, from 16.54% in February 2011 to 28.40% in January 2012 and 29.84% last month. But NetMarketShare reports lower usage of Google's browser: just 18.90% in February, down from 19.11% in December 2011 and 18.94% in January 2012.
NetMarketShare says Firefox (20.92%) is still ahead of Chrome, whereas StatCounter has shown Chrome as being ahead of Firefox since last November.
The differences between the two sets of figures can be explained in terms of differing choices of visitors to the various sites that use these analytics services, and to regional variations. For example, StatCounter reports Internet Explorer usage is much higher in North America than in Africa, and Chrome use is higher in Europe than in Oceania.