There is an exciting new project in pythonic interactive data visualization that I have my eye on: mpld3. It plays well with matplotlib-based pretty plotting packages, and has the beginnings of a plugin framework for adding custom interactivity.
I used it to mock up a Cartesian fish eye distortion plot, something I’ve wanted for DisMod-MR ever since I learned about it. (Sometimes the interactivity doesn’t work in that notebook, and requires reloading everything… cutting edge software has some rough edges.)
Healthy Algorithms 
When I was finding all the links for this post, I found a similar-seeming project for R: https://github.com/ramnathv/rCharts