Xamarin is a software company that was founded in 2011 and is based in San Francisco, California. The company is known for its Xamarin platform, which allows developers to create mobile applications for multiple platforms, including iOS, Android, and Windows, using the same codebase. This allows developers to write their code once and use it on multiple platforms, reducing the time and effort required to create and maintain mobile applications. Xamarin was acquired by Microsoft in 2016 and is now a part of the .NET family of products.