According to the Daily Herald, Microsoft cloud chief, Scott Guthrie wrote up a proposal to acquire GitHub and then filed away in his drawer.

"We would have screwed it up, and developers -- many of whom viewed Microsoft as public enemy No. 1 for its attacks on freely distributed open-source software -- would have rioted.”

He said that the open-source world “rightly looked at us at the time as the antichrist" and Vole didn’t have the credibility it now has around open source.

Since then, Microsoft has turned itself into one of the biggest developers of open-source software and has persuaded customers to trust applications built using rival tools and programs to Microsoft's Azure cloud-computing service, boosting Azure revenue and usage.

More than 60 percent of the company's team that works with cloud-app developers were hired for their expertise in non-Microsoft programming tools or cloud services. A full version of the open-source Linux operating system is even being added to Windows. The efforts are bringing new software builders to the Microsoft camp.

Last June, Guthrie and Microsoft Chief Executive Officer Satya Nadella finally unveiled an agreement to acquire GitHub. While there was still some initial agitation in the developer community and rivals gained some refugee users from GitHub, one year later the deal is noteworthy mainly for how little drama it's caused. Most GitHub users just continued putting their code there.

"Some were upset, but because Microsoft had spent years building up goodwill with the open-source community. There was a knee-jerk sort of 'remember, they're the Great Satan' reaction, but it was half-hearted."

So far, Microsoft has done little to interfere with GitHub. Like Microsoft acquisition LinkedIn, GitHub has its own CEO and is run independently. The prevailing management ethos seems to be to try to add features users appreciate -- for example, making some private code repositories free to host -- while not messing with anything they liked.