I didn't even know what BNF was when I had the idea ;)
It's still on my list of short projects. I have a lot of learning to do, knowing nothing about writing parsers and such. Yes, I know I could probably hack it together with a bunch of garbage Python. But that just does not sound fun to write, let alone maintain.
I also find another project called Viz.js[1]. It's graphviz in javascript. Looks promising. It's hard to choose between this two. On the one hand is very simple syntax, and on the other hand more flexibility.
It's still on my list of short projects. I have a lot of learning to do, knowing nothing about writing parsers and such. Yes, I know I could probably hack it together with a bunch of garbage Python. But that just does not sound fun to write, let alone maintain.