Downlaod : http://www.sonarsource.org/downloads

Sonar is an open platform to manage code quality.
Sonar is a web-based application. Rules, alerts, thresholds, exclusions, settings… can be configured online. By leveraging its database, Sonar not only allows to combine metrics altogether but also to mix them with historical measures.
Sonar has got a very efficient way of navigating, a balance between high-level view, dashboard, TimeMachine and defect hunting tools. This enables to quickly uncover projects and / or components that are in Technical Debt to establish action plans.