Xamarin

Xamarin was a software company and development-platform brand focused on cross-platform application development with C# and the .NET ecosystem. It was founded in May 2011 by Miguel de Icaza and Nat Friedman, engineers associated with the Mono project, after Attachmate's acquisition of Novell created uncertainty around the future of Mono and related commercial mobile products. Xamarin assumed stewardship of Mono and developed commercial tools based on the Common Language Infrastructure and Common Language Specifications, enabling .NET developers to build applications for multiple operating systems. The platform's central proposition was code sharing without giving up access to native platform capabilities. Developers could use C# and familiar .NET libraries while producing applications with native user interfaces and access to platform-specific APIs on Android, iOS, macOS, Windows, tvOS and watchOS. Xamarin.iOS and Xamarin.Android were the principal platform-specific implementations, while Xamarin.Forms offered a shared user-interface abstraction that mapped common controls to native controls on supported platforms. The tooling integrated with Microsoft Visual Studio and, for macOS users, Visual Studio for Mac. Xamarin also supplied testing, debugging, component distribution and code-analysis tools, including Xamarin Test Cloud, Xamarin Studio, Xamarin.Mac and the .NET Mobility Scanner. Xamarin expanded rapidly during the mid-2010s. The company raised venture financing, acquired the mobile testing platform LessPainful in 2013 and acquired the Java mobile-development company RoboVM in 2015. It reported more than 1.4 million developers in 120 countries by April 2017, and organizations including 3M, AT&T and HP were cited as users of its technology. The company became strategically important to Microsoft's effort to make .NET a productive platform for mobile development beyond Windows. Microsoft announced an agreement to acquire Xamarin on February 24, 2016. The transaction made Xamarin a Microsoft subsidiary and brought its SDKs, tooling and developer community into Microsoft's broader .NET and Visual Studio strategy. At Microsoft's Build 2016 conference, Microsoft announced that the Xamarin SDK would be open-sourced and made available as part of Visual Studio, with Mono relicensed under the MIT License. Xamarin functionality was subsequently integrated into Visual Studio editions, reducing the distinction between Xamarin's standalone products and Microsoft's principal development environment. Microsoft later positioned .NET Multi-platform App UI, or .NET MAUI, as the successor to Xamarin.Forms. Announced as part of the .NET 6 direction in 2020 and released in 2022, .NET MAUI extended the shared .NET application model and added macOS support through Mac Catalyst. Microsoft ended support for the Xamarin SDKs, including Xamarin.Forms, on May 1, 2024. The company recommended migration to .NET MAUI, marking the end of Xamarin as a supported standalone application-development platform even though its concepts, code and technologies continue to influence Microsoft's cross-platform .NET tooling.

Xamarin's roots lay in Ximian, the company launched by Miguel de Icaza and Nat Friedman in 1999 around the GNOME project and related open-source software. After Microsoft announced the .NET Framework in 2000, de Icaza investigated whether a compatible implementation could run on Linux. The resulting Mono project began in July 2001 and implemented important parts of the .NET development model on non-Windows systems. Novell acquired Ximian in 2003 and subsequently developed Mono-based products, including MonoTouch for iOS and Mono for Android. Novell was acquired by Attachmate in April 2011. Attachmate announced layoffs affecting Mono developers, creating uncertainty about the project's commercial direction. In May 2011, de Icaza announced Xamarin as a new company that would continue developing and supporting Mono while creating a new generation of mobile products. The name followed the Ximian naming tradition and was formed by substituting X for the initial letter of Tamarin, a related project name. Because MonoTouch and Mono for Android had previously been commercial offerings associated with Novell, Xamarin's legal right to continue the work was initially questioned. In July 2011, Novell and Xamarin announced a perpetual license covering Mono, MonoTouch and Mono for Android. This agreement enabled Xamarin to become the formal commercial steward of the technologies and to develop them independently. The company expanded its product range during the next several years. It released XobotOS, an experimental Android implementation written in C#, in 2012; introduced Xamarin.Mac later that year; and released Xamarin 2.0 in February 2013. Xamarin 2.0 combined the Xamarin Studio development environment with Visual Studio integration, allowing developers to create Android, iOS and Windows applications inside a mainstream .NET workflow. Xamarin acquired the mobile testing platform LessPainful in 2013 and launched Xamarin.Forms in 2014. Forms provided shared controls and a XAML-based interface model that mapped to native controls on supported platforms. Xamarin also raised substantial venture financing. It announced a $16 million Series B round in 2013 and a $54 million Series C round in 2014. In 2015, it acquired RoboVM, a Java-based platform for developing applications with native mobile interfaces. RoboVM was later discontinued by Microsoft, with subscriptions ending after April 2017. Microsoft announced its acquisition of Xamarin in February 2016. After the transaction, Microsoft made Xamarin increasingly part of its .NET and Visual Studio strategy. At Build 2016, Microsoft announced open-source availability for the Xamarin SDK, free inclusion across Visual Studio editions and MIT licensing for Mono. Xamarin Studio was eventually discontinued on Windows in favor of Visual Studio tooling, while the macOS development experience moved into Visual Studio for Mac. Microsoft announced in 2020 that Xamarin.Forms would be brought into the next generation of .NET as .NET MAUI. .NET MAUI was released in May 2022 and became Microsoft's recommended successor for cross-platform .NET application development. Microsoft ended support for all Xamarin SDKs on May 1, 2024, including Xamarin.Forms. Xamarin therefore remains historically important as a bridge between Mono, C#, Visual Studio and native mobile development, but it is no longer a supported standalone platform.

1. 2024Xamarin support ends

   Microsoft ends support for Xamarin SDKs and Xamarin.Forms on May 1 and recommends migration to .NET MAUI.

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2. 2022.NET MAUI is released

   Microsoft releases .NET MAUI as the successor direction to Xamarin.Forms.

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3. 2016Microsoft completes the strategic integration of Xamarin

   Microsoft announces the acquisition, open-source licensing and Visual Studio distribution plans for Xamarin technology.

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4. 2014Xamarin.Forms is introduced

   Xamarin introduces a shared user-interface framework that maps common controls to native platform controls.

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5. 2013Xamarin 2.0 launches

   Xamarin releases Xamarin Studio and Visual Studio integration for cross-platform application development.

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6. 2012XobotOS is released

   Xamarin publishes an experimental Android implementation using C# rather than Java.

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7. 2011Xamarin is founded

   Xamarin is established in May to continue Mono development and create cross-platform mobile-development products.

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8. 2011Perpetual licensing arrangement is announced

   Novell grants Xamarin a perpetual license for Mono, MonoTouch and Mono for Android.

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9. 2001Mono project begins

   The Mono open-source project starts with the goal of bringing key elements of Microsoft's .NET development model to other operating systems.

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10. 1999Ximian is launched

    Miguel de Icaza and Nat Friedman launch Ximian, the organizational predecessor to later Mono and Xamarin work.

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A Microsoft-backed cross-platform .NET development platform that allowed C# developers to create native applications for mobile, desktop and selected other operating systems while sharing code across platforms.

• Xamarin PlatformCross-platform application framework2013

  The core Xamarin platform extended the .NET developer model with libraries, bindings and tools for creating applications with C#. Developers could share business logic and other code across Android, iOS, Windows and macOS while retaining access to native APIs and native user-interface technologies.

• Xamarin.FormsCross-platform user-interface framework2014

  Xamarin.Forms provided a shared control and layout model for mobile applications. Its controls were mapped to native Android, iOS and Windows implementations, and its XAML support gave .NET developers a declarative way to define interfaces. It later became the conceptual predecessor to .NET MAUI.

• Xamarin.iOSNative iOS development framework

  Xamarin.iOS, formerly MonoTouch, enabled C# and .NET developers to build iPhone and iPad applications with access to Apple's native APIs and tooling. It was designed to produce native applications rather than browser-based or purely interpreted mobile experiences.

• Xamarin.AndroidNative Android development framework

  Xamarin.Android, formerly Mono for Android, provided .NET bindings and development tools for Android application development. It allowed C# developers to use Android platform APIs while sharing application logic with other .NET targets.

• Xamarin.MacNative macOS development framework2012

  Xamarin.Mac enabled developers to create native Cocoa applications for macOS using C#. It connected the .NET development environment with Apple's macOS APIs and supported packaging applications for distribution through the Mac App Store.

• Xamarin Test CloudCloud application testing

  Xamarin Test Cloud allowed teams to test mobile applications on real, non-jailbroken devices hosted in the cloud. Its object-based UI testing model was intended to simulate user interactions across a large range of device configurations.

• Xamarin StudioIntegrated development environment2013

  Xamarin Studio was a standalone development environment based on MonoDevelop. It offered C# code completion, debugging, an Android interface builder and integration with Apple's Interface Builder before Microsoft shifted the product strategy toward Visual Studio and Visual Studio for Mac.

• 2024Microsoft ends Xamarin supportStrategy

  Microsoft had completed the transition toward .NET MAUI and announced that the Xamarin product line would reach end of support.

  What changed. Microsoft ended support for Xamarin SDKs and Xamarin.Forms on May 1, 2024, with no further fixes, updates or technical assistance.

  Aftermath. Existing applications were directed toward migration to .NET MAUI or other cross-platform .NET frameworks.

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• 2020Microsoft announces the transition from Xamarin.Forms to .NET MAUIGeneration change

  Microsoft was consolidating its cross-platform application strategy around the unified .NET platform.

  What changed. Microsoft announced that Xamarin.Forms would be merged into the next generation of .NET as .NET Multi-platform App UI.

  Aftermath. .NET MAUI became the successor platform and the recommended migration target for Xamarin.Forms applications.

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• 2016Microsoft agrees to acquire XamarinM&A

  Microsoft sought to strengthen cross-platform development in the .NET and Visual Studio ecosystem.

  What changed. Microsoft signed a definitive agreement to acquire Xamarin. The companies did not disclose the transaction terms.

  Aftermath. Xamarin became part of Microsoft, and its SDKs and tooling were integrated into Visual Studio and the broader .NET strategy.

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• 2016Microsoft open-sources and bundles Xamarin toolingStrategy

  Microsoft wanted cross-platform mobile development to become a standard capability of its developer platform rather than a separate commercial product.

  What changed. Microsoft announced open-source Xamarin SDKs, MIT relicensing for Mono and inclusion of Xamarin features across Visual Studio editions.

  Aftermath. The move lowered access barriers and accelerated the integration of Xamarin capabilities into Microsoft's mainstream development tools.

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• 2011Xamarin assumes stewardship of Mono-related developmentStrategy

  Layoffs and organizational changes following Attachmate's acquisition of Novell created uncertainty around the future of Mono and the related mobile products.

  What changed. Xamarin was formed to continue developing and supporting Mono, MonoTouch and Mono for Android, later formalized through a perpetual license from Novell.

  Aftermath. The arrangement established Xamarin as the commercial home for the Mono-based mobile development platform.

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• 2024Microsoft ends support for Xamarin SDKs

  Microsoft ended support for Xamarin and Xamarin.Forms on May 1, 2024, directing developers toward .NET MAUI.

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• 2016Microsoft agrees to acquire Xamarin

  Microsoft and Xamarin announced a definitive acquisition agreement. The parties did not disclose transaction terms.

  M&A
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• 2016Microsoft integrates Xamarin into Visual Studio and open-sources its SDK

  Microsoft announced broader Visual Studio integration, open-source licensing for Xamarin SDK components and MIT relicensing for Mono.

  Product launch
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• 2015Xamarin acquires RoboVM

  Xamarin acquired the Swedish Java application-development platform RoboVM and initially operated it separately from its main product group.

  M&A
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• 2014Xamarin announces Series C financing

  Xamarin announced a $54 million Series C financing round, bringing its reported total funding to $82 million.

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• 2013Xamarin announces Series B financing

  The company announced a $16 million Series B round led by Lead Edge Capital, with participation from earlier investors.

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• 2013Xamarin announces Xamarin 2.0

  The release introduced Xamarin Studio and deeper integration with Microsoft's Visual Studio development environment.

  Product launch
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• 2011Xamarin is founded to continue Mono development and build mobile products

  Miguel de Icaza announced the formation of Xamarin after the Novell and Attachmate transaction disrupted the previous commercial and organizational home of Mono-related development.

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• 2011Novell grants Xamarin a perpetual license for Mono-related technologies

  Novell and Xamarin announced a licensing arrangement covering Mono, MonoTouch and Mono for Android, clarifying Xamarin's legal stewardship of the projects.

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1. Xamarin
2. What is Xamarin?
3. Xamarin official product page