I'm sort of glad I didn't see VEE before building my picture-drawing tool - I would have given up before I started! But I needed a way to diagram FBP networks - I am very visual, although I have known some programmers who are not...

I don't understand the distinction between code and diagrams: you can code FBP networks without drawing pictures, but I wouldn't be able to visualize them. A chap I know built a network of 200 nodes using stepwise decomposition and never once drew a picture! I can't do that, but it worked for him!

I also don't understand what is meant by "underlying implementation". You can encode your network in XML-style, and in fact we did this on a project I worked on, but basically it's just a list of connections, so I don't see where it matters much what notation you use... Maybe I'm missing something?