Google will continue patching the Chrome browser running on XP beyond Microsoft’s April 2014 cut-off for the still hugely popular operating system.

In an announcement on the Chrome blog, Google’s director of engineering and ‘superintendent of public safety’ Mark Larson argued that simply walking away from a platform with such a large user base was not an option in the short term. Google would continue to offer security updates for Chrome until at least April 2015, he said.

“We recognize that hundreds of millions of users, including a good chunk of current Chrome users, still rely on XP. Moreover, many organizations still run dozens or even hundreds of applications on XP and may have trouble migrating,” said Larson.

“Chrome on XP will still be automatically updated with the latest security fixes to protect against malware and phishing attacks,” he added.

IT admins could use Legacy Browser Support to limit the scope of Chrome web apps on XP to, he pointed out.

As far as Microsoft is concerned, Windows XP retires on 8 April 2014. It is looking like a racing certainty that a sizable number of consumers and some businesses will run it beyond that date either out of apathy or because they can't make the transition in time and have bought extended third-party support.

There is some logic to this; the majority of serious (i.e. exploited) vulnerabilities occur in browsers and their plug-ins. Leaving the OS unpatched is plausible for a short while, at least for businesses able to manage the transition to Windows 7 or 8.

Meanwhile, offering to patch XP SP2 or above Chrome installs costs Google nothing even for older 32-bit versions.

But Larson’s announcement contains the veiled warning that Chrome updates won’t carry on indefinitely.

NetMarketShare’s 2013 numbers give XP a roughly 35 percent market share and falling. Microsoft’s next problem will be Windows 7 which at 45 percent still dwarfs the 8 percent recorded by Windows 8.