Windows Forms
Windows Forms, also known as WinForms, is a free, open-source graphical user interface (GUI) class library for building Windows desktop applications, included as a part of Microsoft .NET, .NET Framework or Mono, providing a platform to write client applications for desktop, laptop, and tablet PCs. While it is seen as a replacement for the earlier and more complex C++ based Microsoft Foundation Class Library, it does not offer a comparable paradigm and only acts as a platform for the user interface tier in a multi-tier solution.