My team has been evaluating the SONAR tool to manage code quality. I was impressed with the features and the user friendliness of the tool. SONAR can be used for both Java and .NET projects. It has a open plug-in architecture that allows any code quality tool to be plugged in.
For example, for static code analysis it combines the power of popular tools such as PMD, checkStyle and FindBugs into an unified user interface that is great to use :)
SONAR also has support for free code coverage tools such as JaCoCo. Code coverage can be measured by unit tests or integration tests. You can even drill down to source code level - something I love to do :)
SONAR also integrates with new tools such as SQALE that have a formal approach for defining code quality in terms of maintainability, Testability, Reliability, Changeability, Efficiency, Security, Portability, Reusability, etc. Overall it is an invaluable tool to access Technical Debt.