Microsoft StyleCop - What is it? And what about FxCop?

I have been in many discussions about how to ensure a certain level of predictability and quality in source code. For those that haven't already discovered it Microsoft StyleCop brings to the table a new offering to complement FxCop in the land of static code analysis. It is important to understand that StyleCop is not a replacement for FxCop and that the two can (and should) live together harmoniously.

Here is a snippet from the initial release (full text here)

"We are very excited to announce the release of a new developer tool from Microsoft, Source Analysis for C#. This tool is known internally within Microsoft as StyleCop, and has been used for many years now to help teams enforce a common set of best practices for layout, readability, maintainability, and documentation of C# source code."