Lightning is a framework for interactive data visualization, including a server, visualizations, and client libraries. The lightning server provides API-based access to reproducible, web-based visualizations. It includes a core set of visualization types, but is built for extendibility and customization. It can be deployed in many ways, including Heroku, Docker, a public server, a local app for OS X and even a serverless version well suited to notebooks such as Jupyter.
Lightning can expose a single visualization to all the languages of data science. Client libraries are available in multiple languages, including Python, Scala, JavaScript, and rstats, with many more in future.