The Maven team is pleased to announce the PMD plugin 1.0 release!

http://maven.apache.org/reference/plugins/pmd

The Maven PMD plugin is a plugin that wraps the PMD framework
(http://pmd.sourceforge.net). PMD is a source checking framework that
works by scanning Java source code and looks for potential problems 
like: unused local variables, empty catch blocks, unused parameters, 
empty 'if' statements, etc.

Changes in this version:

o Moved the PMD plugin from the 
  <link href="http://sourceforge.net/projects/maven-plugins">Maven-Plugins 
  SF project</link> to the Maven project.
o Made the plugin work with PMD 1.04
o Made the plugin work with Maven b9.

Note that this plugin has been tested with Maven beta 9. Using it with
another version of Maven is at your own risks! :-)

You can download the PMD Maven plugin here:
http://www.ibiblio.org/maven/maven/jars/maven-pmd-plugin-1.0.jar

Have fun!
-Vincent