So I'm working on a site right now that will be powered by Perl on the back and d3.js on the front.
And here's what I'm loving about d3, I can feed it CSV files. Yup. Not JSON. Not XML. Good old CSV.
I know, it's a bit primitive. And there's a good chance at some point I end up JSONing everything up. But I love me some CSV. And there are 551 CPAN packages for pushing, pulling, parsing, encoding or otherwise mangling it.