After years of speculation and rumors, it's finally official. Microsoft has acquired cross-platform mobile development company Xamarin for an undisclosed amount.

Scott Guthrie, executive vice president of Microsoft’s Cloud and Enterprise Group, writes:

In conjunction with Visual Studio, Xamarin provides a rich mobile development offering that enables developers to build mobile apps using C# and deliver fully native mobile app experiences to all major devices – including iOS, Android, and Windows. Xamarin’s approach enables developers to take advantage of the productivity and power of .NET to build mobile apps, and to use C# to write to the full set of native APIs and mobile capabilities provided by each device platform. This enables developers to easily share common app code across their iOS, Android and Windows apps while still delivering fully native experiences for each of the platforms. Xamarin’s unique solution has fueled amazing growth for more than four years.

Xamarin currently has more than 15,000 customers in 120 countries. Over 100 of them are Fortune 500 companies, including Alaska Airlines, Coca Cola Bottling, Thermo Fisher, Honeywell, and JetBlue.

While Microsoft's cross-platform efforts have increased and therefore their partnership with Xamarin strengthened, integration was built into Visual Studio, Microsoft Azure, Office 365, and Enterprise Mobility Suite.

Xamarin allows developers to share a C# code base between native Android, iOS, and Windows apps. Microsoft promises to share more at Build and at Xamarin Evolve in April.

Source: ScottGu's Blog via VentureBeat