Microsoft Corp. (NASD: MSFT) now owns two of the top professional networks (it acquired LinkedIn in 2016) with its $7.5 billion acquisition of GitHub announced yesterday, CNBC reported. GitHub is an online platform where developers share code and collaborate, and CNBC stated that it’s where coders can develop a portfolio of their work.

Investment firm Andreessen Horowitz noted that point in a 2012 blog post when it invested $100 million in GitHub, saying it had become the social network for programmers.

“If you are using another programmer’s open source libraries, are interested in what she’s doing or just a fan of her work, you can follow her on GitHub,” according to the post. “If you need to hire great programmers, why look at resumes when you can view a candidate’s actual work on GitHub?”

GitHub’s chief strategy officer also called it “the de facto tool for recruiting technical talent,” in an interview earlier this year, The New York Times reported.

In the deal announced yesterday, Microsoft agreed to pay $7.5 billion in stock for GitHub, according to Microsoft. The acquisition is expected to close by the end of the calendar year, subject to customary closing conditions and completion of regulatory review.

Microsoft Corporate VP Nat Friedman, founder of Xamarin, will assume the role of GitHub CEO. GitHub’s current CEO, Chris Wanstrath, will become a Microsoft technical fellow, reporting to Executive VP Scott Guthrie, to work on strategic software initiatives.

Microsoft stated GitHub will operate independently to provide an open platform for all developers in all industries. 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 to any operating system, cloud or device.

However, some GitHub users fear that Microsoft is hostile to open source and will do something to GitHub to undermine the open-source projects that depend on it, Ars Technica reported. Comments suggest not any specific concerns but a widespread lack of trust, at least among certain developers, of Microsoft’s behavior, motives, and future plans for the service.