Is there any software, preferably free, preferably supporting drag & drop, preferably supporting save & load to ease the creation diagrams like these?
(source: tikilive.org)
Answer
I would use yEd* not only does this tool draw these it also makes automatic layouts for your nodes. Other software would include MS Visio.
Image 1: A image made with yEd illustrator combo (yEd made preliminary layout)
Another approach would be to use Graphviz, which could make your graphs 100% without your input from a data source easily.
Related post:
* yEd is free and can be run over web with java if needed.
Attribution
Source : Link , Question Author : hanshenrik , Answer Author : Community