Forty percent of all virtual machines in Microsoft's Azure cloud are now running Linux.

(Credit: @BrianLinuxing)

That stat is courtesy of a tweet on Oct. 31 from the Microsoft Developer UK account. The tweet, hashtagged as #FutureDecoded, seemingly is connected to information that Microsoft officials shared at the company's conference in London today.

Community Manager Brian Byrne (@BrianLinuxing) retweeted the Microsoft Developer UK tweet, adding: "Only 40%? Come on! Its more than that:)."

Previously, the most recent stat on how many VMs in Azure are running Linux dates back to June 2016, when Microsoft officials said nearly one in three Azure virtual machines were running Linux.

Microsoft launched Azure on Oct. 27, 2008 (as then Chief Software Architect Ray Ozzie recently reminded me on Twitter). When Microsoft first launched Azure, it was purely a platform-as-a-service play. Microsoft added infrastructure-as-a-service support to its cloud platform in 2012 and added Linux support at that time.

Microsoft currently supports a variety of Linux flavors on Azure, including CentOS, CoreOS, Debian, Oracle Linux, Red Hat Enterprise Linux, SUSE Linux Enterprise, openSUSE, and Ubuntu.

Yesterday, Microsoft noted that Azure customers creating VMs in their labs can now opt for a Kali Linux image. Kali Linux is a Debian-derived Linux distribution designed for digital forensics and penetration testing.