It’s no secret that Microsoft has gone from open source pariah to open source contributor. What hasn’t been appreciated is just how significant those contributions have been. Given its history, it would be significant if Microsoft simply approached parity of contributions with industry peers like IBM or Google. Instead, Microsoft’s open source contributions dwarf those of every other company on the planet, barring Google, as GitHub data reveals.

Yes, that’s right: Microsoft is the world’s biggest open source company measured by contributrors, and by a wide margin.

Up and to the right

In a race to criticize AWS for not giving enough back to open source (a smear that Hadoop founder Doug Cutting labeled “insanity”), some began to dig into GitHub data for proof one way or another. Felipe Hoffa, a developer advocate for Google, did perhaps the best work, uncovering that, in fact, AWS contributes relatively little to open source projects.

In so doing, however, he also discovered data at the other end of the table, showing that Microsoft and Google are the top-two contributors, and by a big margin:

In terms of people contributing, Microsoft wins handily, with 1,303 contributors (compared to Google’s 911). In terms of the number of repositories (and the significance thereof), Google tops the charts, with 1,116, compared to Microsoft’s 832. As for the importance of the projects, Hoffa uses GitHub stars to measure importance, and Google essentially doubles Microsoft’s tally (538,687 stars vs. 263,525 stars).

SEE: Open source vs. proprietary software: A look at the pros and cons (Tech Pro Research)

No one else comes close. Not even Red Hat, the only company with a 100% commitment to contribute all of its code under an open source license. It’s a bit breathtaking.

A question of business model

Part of the big love for open source stems from a desire to reach developers. This isn’t the whole story, of course, because no cloud service is more popular than AWS, which gives away comparatively little code. What it does contribute, however, is a bevy of services that are “open” in the sense of being easy to find, easy to use, and easy to afford. Both Google and Microsoft have been playing catch-up in those areas.

Developers, however, only tell part of the story. No matter the importance of developers, neither Microsoft nor Google would be contributing so much code but for the fact that their respective business models, based on subscription software services, allow and even encourage them to do so. This is particularly true of Microsoft, which has done an excellent job of enabling developers for decades, but always with proprietary software.

SEE: Why it’s pointless to criticize Amazon for being “bad” at open source (TechRepublic)

Now it doesn’t need to. Someone may be running $0.00 Linux, but if they’re running it on Azure, Microsoft is earning more than $0.00. Ditto MySQL or any other open source project you can think of. Indeed, the more great code Microsoft gives away, the more likely developers will run that software on Azure. And if, like Google with Kubernetes, they make their open source projects a great on-ramp to running in their cloud, open source becomes a force multiplier for their cloud business, with open source complements feeding a proprietary core (the core being all the services running on Azure or other clouds).

Microsoft arguably invests more people in contributing to open source projects because it has had the most work to do to reverse a well-earned reputation for animus toward open source. Soon few will remember the bad old days of Microsoft dubbing open source “un-American” or contrast to capitalism. In the process, Microsoft will demonstrate that not only is open source not antithetical to capitalism, it’s actually the heart of free market software liberalism.