Microsoft Acquires GitHub for US$7.5 Billion

Microsoft announced its acquisition of GitHub on 4 June 2018 and completed it on 26 October 2018. The announced price was US$7.5 billion in Microsoft stock, not cash. In between, on 19 October, the European Commission approved the deal without conditions. After the acquisition GitHub was run by Nat Friedman, the founder of Xamarin, reporting to Scott Guthrie, head of Microsoft's cloud group.

The US$7.5 billion figure was the value of the shares at the time of the announcement. When a deal is paid in stock, the value at completion moves with the share price, so any statement that Microsoft paid US$7.5 billion should be read with that caveat.

From announcement to completion

The June announcement said the deal, subject to customary closing conditions and regulatory review, was expected to close by the end of the calendar year. It closed at the end of October.

What Microsoft bought

Microsoft's announcement described GitHub as the world's leading software development platform, where more than 28 million developers learn, share and collaborate. Since its public launch in 2008, GitHub had become the centre of open-source development: a place to share Git repositories on the web and to change other people's code through pull requests and issues.

CEO Satya Nadella said in the announcement: "Microsoft is a developer-first company, and by joining forces with GitHub we strengthen our commitment to developer freedom, openness and innovation." He added that Microsoft recognised the community responsibility it was taking on.

The promise of independence

Developers were wary precisely because the buyer was Microsoft. According to The Register, on 1 June 2001 Microsoft's then CEO Steve Ballmer told the Chicago Sun-Times that "Linux is a cancer that attaches itself in an intellectual property sense to everything it touches." The company that had treated open-source licensing as a threat was now buying open source's biggest home.

Microsoft answered with specific commitments from the first day:

• GitHub would retain its developer-first ethos and operate independently
• It would remain an open platform for developers in all industries
• Developers would still be able to use the programming languages, tools and operating systems of their choice, and deploy their code to any operating system, any cloud and any device

The completion announcement in October repeated that GitHub would retain its developer-first ethos, operate independently and remain an open platform.

The people

Xamarin, the company Friedman founded, had itself been acquired by Microsoft in 2016. Putting a long-time open-source figure in charge of GitHub was part of how Microsoft tried to make the promise of independence credible.

Why Brussels said yes

The European Commission cleared the deal unconditionally on 19 October 2018. As quoted by GeekWire, the Commission's press release said: "The market investigation confirmed that Microsoft would not have the market power to undermine the open nature of GitHub to the detriment of competing DevOps tools and cloud services." Such behaviour, it went on, would reduce the value of GitHub for developers, who were willing and able to switch to other platforms.

The regulator did not rely on a mechanism to enforce Microsoft's promises. It relied on the market: if Microsoft broke them, users could leave.

After the deal

Three years later, on 29 June 2021, GitHub and OpenAI released GitHub Copilot as a technical preview, suggesting code inside the editor. Given Microsoft's 2019 investment in OpenAI, GitHub had ended up at the point where Microsoft's AI strategy met developers.

On 11 August 2025 Thomas Dohmke, who had succeeded Friedman as CEO, announced on the GitHub blog that he was leaving. He said he would stay through the end of 2025 to guide the transition, and that GitHub and its leadership team would continue their mission as part of Microsoft's CoreAI organisation. In the same post he wrote that GitHub had more than 1 billion repositories and forks and over 150 million developers — roughly five times the 28 million counted at the time of the acquisition, seven years earlier.

GitHub, which Microsoft had promised to run independently, was thus folded into its AI organisation.

Where it fits

The acquisition is a clear marker of Microsoft's turn towards open source under Nadella, who became CEO in 2014 (see his appointment). The Microsoft of the 1990s had fought the antitrust case over its Windows monopoly; the Microsoft of 2018 took on the home of code that is deployed to other companies' operating systems and clouds.

For the company see Microsoft; for the wider story, the Microsoft timeline and the open-source timeline.