We've seen in this book that there are many tools available to render maps from OpenStreetMap data, but they all have different ways of creating rendering rules that differ to lesser or greater extents. While this allows you to get the most from each rendering application, it also means that creating the same style for different applications means writing new sets of rules for each one.
MapCSS is an effort to produce a unified stylesheet language for OpenStreetMap-based maps that any rendering or editing application can use. It uses the same syntax as the World Wide Web Consortium recommendation Cascading Style Sheets (CSS)—the language used for web stylesheets.
Designers creating rendering rules for OpenStreetMap would no longer need to write separate sets of rules for each rendering application they wanted to use, but instead would write MapCSS stylesheets, which are then either used natively by the application or translated into the...