The Microsoft product umbrella is getting larger, this time with the acquisition of Xamarin, a San Francisco-based startup that helps developers build apps on platforms such as Microsoft’s C# programming language.

The deal is expected to close this month. Xamarin CEO and cofounder Nat Friedman announced the deal on the startup’s blog in late-February.

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Xamarin CEO Nat Friedman. Photo courtesy Wikipedia.

“This acquisition is a new beginning for Xamarin—the company and its products—and is an opportunity to help many, many more developers build great apps,” Friedman wrote. “Like many of you, I see Microsoft and Xamarin as a perfect fit.”

The startup was founded four years ago, and has grown to more than 350 employees, 15,000 customers, and 1,300,00 developers. The company has offices in 14 countries across the globe.

Friedman cited Microsoft’s cloud- and mobile-first strategy as a reason for the partnership.

Scott Guthrie, executive vice president of Cloud and Enterprise Group at Microsoft, wrote on the official Microsoft blog that Xamarin has been a longstanding partner and Microsoft has previously built Xamarin integration into Visual Studio, Microsoft Azure, Office 365, and Enterprise Mobility Suite. The acquisition will take that work even further, Guthrie wrote.

More details are expected at both the Microsoft Build Developer conference and the Xamarin Evolve conference.