Ask HN: Tools for Visualising Baysian Networks?

I've searched high and low but can't find a link previously submitted to HN: It was a really neat visual tool to make Bayesian calculations from a DAG.

The user entered priors for various quantities, and for the correlation between them, and the interface would show a conditional posterior distribution... it was a way of quickly simulating a range of outcomes given non-point estimates for contributing variables. I think it was all written in JS – the UI was quite slick.

If anyone can remember what this was would be incredibly grateful!