|Headquarters||San Francisco, California|
|Key people||Miguel de Icaza, Nat Friedman|
Xamarin is a San Francisco, California based software company created in May 2011 by the engineers that created Mono, MonoTouch and Mono for Android which are cross-platform implementations of the Common Language Infrastructure (CLI) and Common Language Specifications (often called Microsoft .NET).
With a C# shared codebase, developers can use Xamarin to write native iOS, Android, and Windows apps with native user interfaces and share code across multiple platforms. Xamarin has over 505,000 developers in more than 120 countries around the world as of February 2014.
Ximian Founding and Acquisition
In June 2000, Microsoft first announced their .NET Framework. Miguel de Icaza of Ximian began investigating whether a Linux version was feasible. The Mono open source project was launched on July 19, 2001. Ximian was bought by Novell on August 4, 2003, which was then acquired by Attachmate in April 2011.
Founding of Xamarin
On May 16, 2011, Miguel De Icaza announced on his blog that Mono would be developed and supported by Xamarin, a newly formed company that planned to release a new suite of mobile products. According to De Icaza, at least part of the original Mono team had moved to the new company.
After this announcement, the future of the project was questioned, since MonoTouch and Mono for Android would now be in direct competition with the existing commercial offerings owned by Attachmate. It was not known at the time how Xamarin would prove they had not illegally used technologies previously developed when they were employed by Novell for the same work.
In July 2011, however, Novell - now a subsidiary of Attachmate - and Xamarin announced that Novell had granted a perpetual license for Mono, MonoTouch and Mono for Android to Xamarin, which formally and legally took official stewardship of the project.
In December 2012, Xamarin released Xamarin.Mac, a plugin for the existing MonoDevelop Integrated development environment (IDE), which allows developers to build C#-based applications for the Apple OS X operating system and package them for publishing via the Apple App Store.
In February 2013, Xamarin announced the release of Xamarin 2.0. The release included two main components: Xamarin Studio, which bundled Xamarin's previous, separate iOS, Android and Apple OS X development tools into a single application; and integration with Visual Studio, Microsoft's IDE for the .NET Framework, allowing Visual Studio to be used for creating applications for iOS and Android, as well as for Windows.
Xamarin 2.0 was released in February 2013, which unified Xamarin's previous, separate iOS, Android and OS X development tools into a single platform. Xamarin.iOS and Xamarin.Android make it possible to do native iOS, Android and Windows development in C#, with either Xamarin Studio or Visual Studio. Developers re-use their existing C# code, and share significant code across device platforms. The product was used to make apps for several well-known companies including 3M, Target, AT&T, and HP.  Xamarin integrates with Visual Studio, Microsoft's IDE for the .NET Framework, extending Visual Studio for iOS and Android development. Xamarin also released a component store to integrate UI controls, backend systems, cloud services and 3rd party libraries directly into mobile apps.
Introduced in Xamarin 3 on May 28, 2014 and allows to use a portable controls subsets that are mapped to native controls of Android, iOS and Windows Phone.
Xamarin Test Cloud
Xamarin Test Cloud makes it possible to test mobile apps written in any language on real, non-jailbroken devices in the cloud. Xamarin Test Cloud uses object-based UI testing to simulate real user interactions.
Xamarin for Visual Studio
Xamarin claims to be the only IDE that allows for native iOS, Android and Windows app development within Microsoft Visual Studio. Xamarin supplies add-ins to Microsoft Visual Studio that allows developers to build iOS, Android, and Windows apps within the IDE using code completion and IntelliSense. Xamarin for Visual Studio also has extensions within Microsoft Visual Studio that provide support for the building, deploying, and debugging of apps on a simulator or a device. In late 2013, Xamarin and Microsoft announced a partnership that included further technical integration and customer programs to make it possible for their joint developer bases to build for all mobile platforms. In addition, Xamarin now includes support for Microsoft Portable Class Libraries and most C# 5.0 features such async/await. CEO and co-founder of Xamarin, Nat Friedman, announced the alliance at the launch of Visual Studio 2013 in New York.
Xamarin Studio, a standalone IDE for mobile app development, was released in February 2013 as part Xamarin 2.0 and is based on the open source project MonoDevelop. In addition to a debugger, Xamarin Studio includes code completion in C#, an Android UI builder for creating user interfaces without XML, and integration with Xcode Interface Builder for iOS app design. 
Xamarin.Mac was created as a tool for Apple technology application development using the C# programming language. Xamarin.Mac, as with Xamarin.iOS and Xamarin.Android, gives developers up to 90% of code reuse across iOS, Android and Windows. Xamarin.Mac gives C# developers the ability to build fully native Cocoa apps for Mac OS X and allows for native apps that can be put into the Mac App Store. 
.Net Mobility Scanner
Xamarin’s .Net Mobility Scanner lets developers see how much of their .NET code can run on other operating systems, specifically iOS, Android, Windows Phone, and Windows Store. It is a free web-based service that uses Silverlight.
- Visionary in the Gartner Magic Quadrant for Mobile Application Development Platforms
- Dr Dobbs Jolt Award: Mobile Development Tools
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