Bugzilla
From APIDesign
Bugzilla is a bug tracking system backed by SQL database. Many open source projects use Bugzilla. NetBeans uses it too.
Throw Away Your Bugtracking System
I've noticed very nice and inspiring article few months ago. It somehow captures something I always had somewhere deep inside me: Leaving tons of bugs open is useless. In March 2010 I started to practise it by announcing that I will close every issue I find that does not match the project owner expectations. I started with 300 bugs in modules of my reponsibility back then. Now, half a year ago I have 15 open issues. I think the article was right. It does not make any sense to keep issues open. Either fix it, if they are producible. Or enhance logging and close as worksforme. Or give up and honestly say that you don't care (e.g. close as won'tfix).
The question however is who's the project owner on an open source project like NetBeans?