PMD 3.4 is out! It features thirteen new rules, an entirely new "migrating" ruleset, new facilities for suppressing warnings with annotations, and lots of bug fixes and performance improvements. The entire changelog is here and the release itself is here.
I'm happy about the "migrating" ruleset; I hope it's the start of a good collection of ideas for improving code as a project moves from one JDK version to the next. Right now it has some fairly straightforward suggestions - replace Hashtable with Map, don't use 'enum' as an identifier - lots more to come!
Thanks to all the folks who contributed to this release - Johan Stuyts wrote several rules and made some nice grammar improvements, Allan Caplan wrote two rules and contributed a lot of good suggestions and discussions, Fabio Insaccanebbia wrote two rules, Andriy Rozeluk reported various bugs and suggested several excellent rules, Noel Grandin reported several bugs, and Derek Hofmann suggested various CPD improvements. A full credits list is here.
As always... if you're using PMD, get the book, PMD Applied!