This is a simple d3.js tree diagram that is generated from 'flat' data as used as an example in the book [D3 Tips and Tricks](https://leanpub.com/D3-Tips-and-Tricks).

It is derived from the Mike Bostock [Collapsible tree example](http://bl.ocks.org/mbostock/4339083) but it is a VERY cut down version without the ability to update (collapse).