I will discuss and demo how I use Leaflet, UtfGrids, and D3.js in concert to view and interact with large geographic data on the web. This presentation will not be on d3.js, but rather how to get geographic data from a map to a d3.js chart. I will illustrate why this stack is liquid fast and massively scalable and discus in some detail what a UtfGrid is, how it works and how to create and server them to the web. The context of my work:I am currently working on an open source project called OpenQuake. As a part of this project we are developing a platform which serves as a hub for integrated risk assessment. It allows users to combine seismic hazard, risk and social vulnerability in many different ways in order to obtain output for science, risk assessment, risk awareness and risk management.All my work is available on Github and links will be provided to all demonstrated material.