NCover is a tool that analyzes running code and is able to determine whether code was visited or unvisited while running. Visited code is code that was executed during the running of a process, and unvisited code is code that was not executed.
Man, this is a particularly sensitive topic to me, I must admit. That's mostly because "you must comment all your code" is usually a directive that comes from one of three kinds of people--each non-exclusive of the other:
You can download NCover using the links provided on the left. Once you have it downloaded, you install it (it comes as an msi file, even though I doubt it really needs anything but an xcopy deployment).
Now that we've taken a look at how to run NCover from the command-line and how to use NCoverExplorer to view NCover's output, we can take a look at the features in NCoverExplorer that allow you to do everything right from within its user-interface. If you click on the "Run NCover" button (the fifth from the left on the NCoverExplorer interface), you'll see this window:
NCoverExplorer is a tool that does a great job of displaying NCover's test coverage XML output so that you can quickly make sense of it and put it to good use. To take you through an example, let's imagine I have a struct called PersonName in a C# project called Domain: