Xamarin has been a cross-platform development company for years, specialising in C# in particular. Microsoft had been partnering with Xamarin but has now decided to go the whole hog and has bought the company. The upshot should be more iOS and Android projects also making their way to Windows 10 as universal applications.

From the Microsoft announcement:

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.

Through Xamarin Test Cloud, all types of mobile developers—C#, Objective-C, Java and hybrid app builders —can also test and improve the quality of apps using thousands of cloud-hosted phones and devices. Xamarin was recently named one of the top startups that help run the Internet.

We have had a longstanding partnership with Xamarin, and have jointly built Xamarin integration into Visual Studio, Microsoft Azure, Office 365 and the Enterprise Mobility Suite to provide developers with an end-to-end workflow for native, secure apps across platforms. We have also worked closely together to offer the training, tools, services and workflows developers need to succeed.

With today’s acquisition announcement we will be taking this work much further to make our world class developer tools and services even better with deeper integration and seamless mobile app dev experiences. The combination of Xamarin, Visual Studio, Visual Studio Team Services, and Azure provides a complete mobile app dev solution that provides everything you need to develop, test, deliver and instrument mobile apps for every device. We are really excited to see what developers build with it.

All of which has to be good news for the Windows 10 ecosystem as a whole, with more and more services and projects appearing for the platform.