Scott Hanselman has been on a roll lately with his posts and twits. Today he writes “Question to .NET Programmers: what is the difference between the System.* and Microsoft.* namespaces?”

This is an important question and one that I can’t say I truly know the answer too. I had always assumed it was based on either the idea that System.* was part of the core framework where as Microsoft.* was for Microsoft specific functionality. For instance, it would be expected that much or all of the System.* functionality would be replicated on many other platforms where as Microsoft.* would not.

Certainly this is true for the very basic feature set such as the common types but it is not true for System.Windows.Forms. Which begs the question that I always wondered: why is Windows.Forms where it is? I always expected it to be in Microsoft.Windows.Forms as it is a Windows specific implementation based on many of the Win32 controls.