We don’t have a generalizable library right now. Most of the time, it should be as easy as changing some visual feature of the data in a mouseover function. For example:

https://github.com/wpivis/hindsight/blob/master/demos/hindsight-metafilter/coffee/from_coffee.js#L114

or

https://github.com/wpivis/hindsight/blob/master/demos/hindsight-255charts/js/main.js#L303

We’ve talked about creating a d3 library (for developers) or browser extensions (for users) to make it even easier, but we’re not there yet. If you have any ideas, let us know!