High Quality Content by WIKIPEDIA articles! The Microsoft .NET Compact Framework (.NET CF) is a version of the .NET Framework that is designed to run on resource constrained mobile/embedded devices such as personal digital assistants (PDAs), mobile phones, factory controllers, set-top boxes, etc. The .NET Compact Framework uses some of the same class libraries as the full .NET Framework and also a few libraries designed specifically for mobile devices such as .NET Compact Framework controls. However, the libraries are not exact copies of the .NET Framework. The ones in the .NET Compact Framework are scaled down to use less space.