Google's Android has overtaken Windows to become the world's first-choice platform for accessing the internet, according to number cruncher StatCounter.
Android pipped Windows by 0.02 of a percentage point to snatch the title of most popular operating system by internet user, StatCounter said.
Android claimed 37.93 per cent market share with Windows on 37.91 per cent in March.
Apple's iOS operating system for iPhones and iPads was third most popular at 13.09 per cent.
StatCounter's data is based on 15 billion page views per month of 2.5 million sites.
This is the first time Windows has been bested, with StatCounter calling the March figures a "milestone in technology history and the end of an era".
"It marks the end of Microsoft's leadership worldwide of the operating system market which it's held since the 1980s," chief executive Aodhan Cullen said in a statement.
Windows continues to dominate the desktop OS market, with 84 per cent of PCs accessing the internet running Microsoft's operating system.
StatCounter's results reflect a number of long-term shifts in the computing business.
One has been the meteoric rise of the smartphone and tablet, with double-digit growth up until a year ago.
The market is still expanding – by around 7 per cent a year – but Gartner has noted that it is saturated to the point where double-digit growth has finished.
Sales of traditional PCs have flagged, meanwhile, falling year on year. 2016 marked the fifth consecutive year of declining PC sales, according to Gartner, which blamed the long-term change in people's tastes.
As the smart device has ascended, so too has Android; Apple was first in January 2007 with the iPhone, setting the standard for smartphones, but it's Google – 10 months behind – with Android that dominates.
And it dominates with Samsung.
Along the way, Microsoft has done what nobody thought entirely possible in a booming market and delivered a failed mobile phone strategy.
Windows on smartphones has crashed and burned – just 0.3 per cent of the market.
Android had 81.7 per cent of the global smartphone OS market by the fourth quarter of 2016 with Samsung the largest phone maker, 20.5 per cent.
Smartphone sales are outpacing PCs by miles: Samsung sold 306,446,600 units for that fourth quarter while Lenovo, the world's largest PC maker by shipment, shifted a relatively meagre 15,871,000 units.
It will be instructive to see whether April onwards consolidates the trend found by StatCounter, with Android opening a wider lead over Microsoft's operating system, or if, somehow, Windows can resist these long-term shifts and regain its lead.
In the meantime, Microsoft can still profit: the company has tied many Android device makers into paying it royalties through patent licensing deals.®