In some of my jobs I’ve used MS Visio to create diagrams of all types, such as system diagrams and processing flow diagrams. It’s always been a good tool for creating these diagrams but is not part of MS Office package, therefore requires a separate purchase, which isn’t always possible.

Recently, I discovered a great open source (thus free) program called Dia. This provides almost all the features of Visio that I actually used and is highly recommended. According to their homepage, it runs on GNU/Linux, Mac OS X, Unix and Windows – I’ve used the Windows version with no problems. You can see some screenshots here.

I’ve been using Dia to create a Software Testing diagram, so that I can visualise the various stages of Software Testing, as covered in the ISEB/ISTQB Foundation certification that I’m currently studying. Below is an example of a diagram I’m working on, created in Dia.

Dia saves in its own .dia format but you can Export to all sorts of formats, including .png which is the format of the diagram example above.

Dia also looks useful for producing UML diagrams, as it has a specific set of UML drawing tools that can be selected. That feature alone could save users a fortune as many UML-specific programs can be very expensive.

Hopefully, next on the list for Dia’s creators will be an XML Spy style app.