[[Metro-style app]]s were originally designed for specific form factors and leverage the power of the Windows operating system. Two subset of the .NET Framework is available for building Metro-style apps using [[C Sharp (programming language)|C#]] or [[Visual Basic]]: One for [[Windows 8]] and [[Windows 8.1]], called ''.NET APIs for Windows 8.xMicrosoft Store apps''. Another for [[Universal Windows Platform]] (UWP), called ''.NET APIs for UWP''. This version of .NET Framework, as well as the runtime and libraries used for Metro-style apps, is a part of [[Windows Runtime]], the new platform and development model for Metro-style apps. It is an ecosystem that houses many platforms and languages, including [[.NET Framework]], [[C++]] and [[HTML5]] with [[JavaScript]].<ref>{{cite web|title=.NET for Windows apps|url=https://msdn.microsoft.com/en-us/library/windows/apps/br230232.aspx|website=[[MSDN]]|publisher=[[Microsoft]]|access-date=26 January 2016|archive-date=20 February 2016|archive-url=https://web.archive.org/web/20160220182055/https://msdn.microsoft.com/en-us/library/windows/apps/br230232.aspx|url-status=live}}</ref>
