Copy / Paste Detection
Sonar enables to search and report on Copy / Paste of source code. To do this, Sonar can rely on PMD CPD or Sonar CPD
This is the historical engine to search for copy / paste. Mainly for performances reasons, it only enables to do copy / paste detection within a project and event within a maven module when maven is used.
Since Sonar 2.11, a new Sonar copy paste detection engine has been added that is much more scalable and can detect cross-projects duplications. The switch between the 2 engines can be parameterized, the default being Sonar.