I'll second graphviz, aside from it's standalone strengths it integrates well with doxygen and the two combined make for some great documentation. I use it for

I'll second graphviz, aside from it's standalone strengths it integrates well with doxygen and the two combined make for some great documentation. I use it for sequence charts as well by using sublabels (not sure what they're really called), usually I don't care so much about the sequence but where the choke points in this giant pile of steaming enterprise are: SomeObject[label="<someMethod1> someMethod1 | <someMethod2> someMethod2"]; Foo -> SomeObject:someMethod2;