Can you guess it ?

If you remember my last post, I used an UML diagram to explain the overall architecture of Acegi Security. Can you guess in which tool I made it ?
UML is one of the most well-known standards in the IT world, and many tools have been created to help us design those nifty diagrams. The first tools I met were the full-blown commercial products like Rational Rose or Together. And although they really are good products, with lots of features, it always seemed to me that they were a little fatter and heavier than they should. Is it really that difficult to create a small tool that models UML diagrams ?
Then I discovered Dia, which does a reasonably good job, and is completely free. But it's not an UML tool, it's a general-purpose diagram creator (much like M$ Visio). That can be an advantage, but it also means that certain features, typical in UML only tools, are not present: code generation and reverse-engineering. Although I rarely use those features, sometimes they can be very helpful. Overall, I think it's a good piece of software. However, I never enjoyed how the end result looked like.
So, after Dia, I tried ArgoUML. I was impressed by the different kind of UML diagrams it allowed, including the sequence diagram which is normally the first to be absent. I was just starting to explore ArgoUML when, by chance, I discovered Umbrello. Umbrello also has all the UML diagrams (at least all I can think of), does code generation and some reverse engineering (not tried it though). Normally this kind of tools have only one programming language in mind (when generating code or reverse engineering). Umbrello allows code generation for: Java, C++, JavaScript, Python, Perl, PHP5, SQL and a few others (reverse engineering allows only for C++). So what is the difference to ArgoUML ? ArgoUML also allows code generation to more than one language (although not as many as Umbrello), but I didn't find an option for reverse-engineering. Diagrams aside, ArgoUML has a few additional features relating to project handling and overall it seems a more complete and also a more complex product. In terms of usability I think Umbrello takes the lead: the interface is less cluttered and the overall program is lighter, faster and easier to use. And even comparing to Together, from what I can remember when I used it a few years ago, I prefer Umbrello for it's usability.
So, in conclusion I think both ArgoUML and Umbrello are excellent UML tools, that should be considered before blindly buying the full-blown commercial products.
And the answer to my initial question is: Umbrello...never leave home without it ;)