A small list of open source prototyping and wireframing tools (or related tools):
- http://live.gnome.org/Dia
- http://dub.washington.edu:2007/projects/denim/
- http://cmap.ihmc.us/
- http://compendium.open.ac.uk/
Of course, this list needs a further research and analysis. In the meantime, here it is!
