I would like to try some software like Visio, Rational Rose or similar that allows to design relationship within classes.
I would like software to draw UML Diagrams, and other drawings used for communicating software requirements (Such as Dataflow diagrams and flowcharts).
I also want to be able to use it for brainstorming, so a good annotation feature would be a plus.
It must support export to some commonly used format, such as PDF, so I can show it to my colleagues.
Operating System: Windows