MetacatUI

I'm leaning towards either the Google Visualization API, which is very complete but this puts our project in a place where we are depending on external resources for such a simple function (unlike google Maps which is almost unavoidable).

There is also Chart.js which creates HTML5 canvases. Well documented, simple, but has little interactivity because it is a canvas.

And also NVD3.js, based off D3.js, which is interactive and more complex than Canvas.js and not documented as well.