A plug in for Eclipse that calculates metrics for your code during build cycles and warns you, via the Problems View, of 'range violations' for each metric. You may also export the metrics to various formats for further analysis.
This is an excellent plug-in that will make you think twice before you write ugly code. By striving not to violate some of the basic metrics checked by this plugin, you are going to end up writing a much cleaner and therefore BETTER code. I strongly recommend to everyone.