Any Good-Freeware-UML Editor ?

Can anyone please suggest an UML editor that satisfies below criteria:

a. easy of use
b. preferably freeware. if not a fully functional trailware
c. supports all kinds of UML diagrams like Use Cases, Sequence Diagrams, Class Diagrams etc.

http://jude.change-vision.com/jude-web/index.html

Its definitely not a freeware,
but when i think about any type of architecture diagrams i prefer visio.

Pros:
ease of use 10/10
extensibility : you can make your own "stencils" and use them in any diagrams
portability: I love the export to "EMF" format. EMF (Enhanced Meta File) is a format supported by XP by default and is a vector oriented format (just zoom !!)
also its support in MS Word (direct paste) is good which in my opinion is what you are going to resort to, to do the documentation (unless you are a Linux guy)
Export to JPG,Gif, etc.

Cons:
You cant expect it to generate code from uml diagrams (At least I have not discovered this)

Thank you all for the timely response.

We started working on a new project which is a software maintenance project. We are asked to document the existing code and existing functionality in the project. If we have to document the existing code then I can think of
a. code call flows
b. sequence diagrams
c. data models
d. use cases
e. business process diagrams
etc.

Now my question is, can you share your experiences how to document the existing code ? any books on documenting code ? any urls ? how to layout the document ? what to put first in the document and what to last in the document ? etc.

appreciate your help.

appreciate any JavaRancher's willing to contribute to my post ...

Take a look at ArgoUML from tigris.org. It was adapted to become the commercial product Poseidon from gentleware (they have a "free version. but it lacks some features).

ArgoUML is fairly mature, although it lacks a little polish. Though in part that's because UML is a standard that tends to get interpreted pretty freely, so they spend a lot of time figuring out the best way to represent things.

I got extremely frustrated trying to do UML in Visio. It had this insane idea I was trying to develop a Visual Basic application. And these days, I don't run Windows, so it's not even a viable option anymore.

Thank you Tim.