a leaflet map example using culture grid library location data to create a map of UK libraries.
leaflet allows developers to create maps with 'simplicity, performance and usability' in mind. it is easy to use, beautiful, and performs far better than a lot of other options. the example below for example has around four thousand markers, but leaflet is designed to cope with tens of thousands.
marker cluster is a plugin that clusters points on the map based on the distance between them, and the zoom level of the map. this is in order to conveniently group together points. clicking on a cluster zooms and expands the points to show further detail. hovering over a cluster also shows the boundaries of all the points within that group.