Few months ago I blogged about the release of NDepend v3 Continuous Integration and Reporting Capabilities here. Recently, the NDepend team has released v4 which comes with code rules based on C# LINQ queries (CQLinq), this make code ruling so much more powerful and flexible.
There are couple of new rules available like:
v4 also provides NDepend.API and a dozen of open-source code tool developed with NDepend.API (the Power Tools)
http://www.ndepend.com/API/webframe.html