No, Graphviz is truly free--it's open source, under the Common Public License Version 1.0. And, since no one has described it here yet: aside from making prett

No, Graphviz is truly free--it's open source, under the Common Public License Version 1.0. And, since no one has described it here yet: aside from making pretty-pictures, the really neat thing about Graphviz is that it is declarative--you describe the nodes in your graph (which can include text, shape, color, etc.), specify the connections and voila--Graphviz does the rest. Oh, and you can use it programatically too--there are libraries for many languages, so you could, e.g., have a user submit genealogy data and then spit back a pretty family-tree diagram. Google around and you'll find various interesting things, e.g. this recent (12/08) article on using Graphviz + PHP to generate Oracle schema diagrams: http://oracle.phpmagazine.net/2008/12/drawing_er_diagrams_for_oracle.html http://oracle.phpmagazine.net/2008/12/drawing_er_diagrams_fo...