Dia - Simple and Free UML Drawing Tool

I mentioned ArgoUML in an earlier post.  Now I'll mention Dia for UML diagrams.  ArgoUML can generate code from the UML models.  Tool Dia was inspired by Visio.  Dia cannot generate code, but it is very easy to use.  Its homepage is:
https://wiki.gnome.org/Dia

The Windows installer for Dia can be found here:
http://dia-installer.de/

Here is an example of a sequence diagram drawn with Dia, which calls them lifelines.

You can see the diagram is more sophisticated than what you would draw with PowerPoint.  There is a drop-box in Dia where you select UML diagrams.

It is important to document your designs.  You export your Dia diagram to a picture file in order to paste it into documents.  I found Gimp useful for cropping pictures exported from ArgoUML.  In Dia I draw a simple box, put my diagram inside the box, and the export to jpeg automatically crops the picture around the box I drew.  That makes it easier than ArgoUML for making jpegs to paste into documentation.

Robert

Posts elsewhere about using Dia for UML:
UML Sequence Diagram in Dia?
http://stackoverflow.com/questions/3535717/uml-sequence-diagram-in-dia

How to lengthen lifeline of sequence diagram in Dia?
http://stackoverflow.com/questions/9955587/how-to-lengthen-lifeline-of-sequence-diagram-in-dia

Post about ArgoUML:
http://canrightonsoftwareandprogramming.blogspot.com/2013/06/argouml-free-uml-drawing-tool.html