Microsoft has acquired GitHub for US$7.5 billion, with the provider's 85 million code repositories and 28 million users making it the internet’s largest code repository.
Redmond will hope to accelerate its growth, attract further developers to the Microsoft range of platforms and integrate GitHub with the Azure cloud that is central to the vendor's strategy.
Developers have raised concerns about the impact of the acquisition on the open source community, which Microsoft CEO Satya Nadella attempted to allay in a blog post about his plans.
"First, we will empower developers at every stage of the development lifecycle – from ideation to collaboration to deployment to the cloud," wrote Nadella. "Going forward, GitHub will remain an open platform, which any developer can plug into and extend.
"Developers will continue to be able to use the programming languages, tools and operating systems of their choice for their projects – and will still be able to deploy their code on any cloud and any device."
Second, Nadella said Microsoft will accelerate enterprise developers' use of GitHub, through "direct sales and partner channels", alongside access to the vendor's global cloud infrastructure and services.
"Finally, we will bring Microsoft’s developer tools and services to new audiences," Nadella explained. "Most importantly, we recognise the responsibility we take on with this agreement.
"We are committed to being stewards of the GitHub community, which will retain its developer-first ethos, operate independently and remain an open platform."
Microsoft vice president Nat Friedman will take over as GitHub CEO, while GitHub co-founder Chris Wanstrath will join Microsoft as a technical fellow.
The acquisition is expected to close by the end of the calendar year, subject to customary closing conditions and regulatory review.
What's next for Github?
GitHub was last valued at US$2 billion in 2015 but has never turned a profit, relying on paid accounts for enterprises to subsidise the free personal accounts.
Microsoft already has more than 1,800 repositories on GitHub, making it the most active organisation on the site, and the acquisition will help the tech giant attract a wide range of developers its platforms.
Nadella has been courting open source projects and developers since he joined Microsoft in 2014, but the company's previous animosity towards the community is not forgotten easily forgotten.
The acrimony reached its peak in 2001 when Nadella’s predecessor Steve Ballmer said "Linux is a cancer", but the company has changed tack since then, as moves such as open sourcing its NET programming and joining the Linux Foundation have illustrated.
"Microsoft is all-in on open source," Nadella promised in his blogpost. "We have been on a journey with open source, and today we are active in the open source ecosystem, we contribute to open source projects, and some of our most vibrant developer tools and frameworks are open source.
"When it comes to our commitment to open source, judge us by the actions we have taken in the recent past, our actions today, and in the future."
However, some developers are already turning to GitHub rivals such as GitLab, which reported a tenfold increase in the daily amount of repositories on the service the day before Microsoft announced the GitHub acquisition.
Whether Microsoft's growing embrace of open source and Nadella’s promises will be enough to retain the remaining GitHub users remains to be seen.