Women in Data Meetup, February 2014 The talk introduces a visualisation grammar called spruce-leaf. Spruce-leaf is a declarative format for creating interactive leaflet maps. The talk is aimed at developers and non-developers alike - no programming knowledge is necessary. With spruce-leaf you can describe the visualisation in JSON format: merge your shapefile (e.g. map of CCG areas in the UK) with CSV data, colour the features, add legend and hover-on information box.