Plotly.js is an open source, high-level, declarative charting library, built on top of d3.js and stack.gl. It ships with over 40 chart types, including 3D charts, statistical graphs, and SVG maps. Use [r-plotly] for the R package and [plotly-python] for the Python package.
You can use Plotly to import and analyze data, create beautiful, interactive, browser-based graphs, and then collaborate on your graphs with others. Plotly also has a Python sandbox (NumPy supported), and has APIs for Python, R, MATLAB, Arduino, Julia, Perl, and REST.
You can see more in the gallery.