OpenLayers

Articles about the open source mapping system OpenLayers.

An Introduction To OpenLayers

19th May 2012 - 7 minutes read time

OpenLayers is a powerful and open source mapping solution written in JavaScript that can display mutliple different mapping services on web pages. What this means is that you can create a mapping tool using Google Maps and swap it to use Bing Maps at a later date without having to totally rewrite your code. OpenLayers works by building up a series of layers that fit together to form mapping, tools, information and even utilities like KML parsing and AJAX. Vectors and markers can also be used to add layers of information onto the map.

A map in OpenLayers (and most other mapping services) is essentially a set of images called "tiles". When you load a map all you are doing is loading in a bunch of map tiles which OpenLayers then places in the correct place. As you move around a map or change the zoom factor then other map tiles are loaded in to build the new view of the map.