Free UML/ER diagram tools?

[ultrafilter]

The title pretty much says it all. I need some tools for drawing UML and ER diagrams, and I'd rather not spend any money on them if I can avoid it. What's out there?

[ASAKMOTSD]

The title pretty much says it all. I need some tools for drawing UML and ER diagrams, and I'd rather not spend any money on them if I can avoid it. What's out there?

Oracle JDeveloper (http://www.oracle.com/technology/products/jdev/index.html) is free & it has UML modeling support.

[Digital Stimulus]

Never used one, so I'm not really supplying any info you couldn't easily find yourself. However, I recall seeing a reference to a Java tool; googling brought up this FAQ question (http://www.jguru.com/faq/view.jsp?EID=568126) with a few links.

The first comment mentions Dia (http://en.wikipedia.org/wiki/Dia_(software)), which I have used for charts for academic papers. Don't know how it does with UML, but it's free, open source, and every Linux distro I've used has it listed in its package manager/repository.

If you do settle on one that's particularly good, would you mind a quick followup post?