This license is said to be OSI certified Open Source, but I'd like a second opinion. It's too much legalese for me to deal with this morning: http://www.research.att.com/sw/tools/graphviz/license/ Interestingly, there is this accompnying binary license: http://www.research.att.com/sw/tools/graphviz/license/binary.html Graphviz is one of the best tree graphing tools I've found. I used it to graph the debian pgp web of trust once before. -- see shy jo