Umbrello UML Modeller is a Unified Modelling Language (UML) diagram program for KDE.
Umbrello handles all the standard UML diagram types like use case digrams and class diagrams.
It can generate (output) : ActionScript, Ada, C#, C++, D, IDL, Java, JavaScript, Pascal, Perl, PHP, Python, Ruby, SQL, Tcl and XML Schema.
It can reverse engineer code written in C++, IDL, Pascal/Delphi, Python, Ada and Java, as well as import XMI files generated by external tools.
Some of you may say that this is a Linux only tool. This is not correct since you can easily install it under Windows. Just take a look at the installation info below.
Under windows you have to
1) Go to : http://windows.kde.org and download the kdewin-installer-gui-latest
2) Use the latest KDE release
3) Search for the packet umbrello
4) The installation is at C:\Program Files\KDE
5) Now you can run Umbrello C:\Program Files\KDE\bin/umbrello.exe