Getting started with OpenLayers

In the world of open source web mapping interfaces, the biggest and most robust one is OpenLayers. OpenLayers was first released in 2006 by MetaCarta Labs. After 2007, it became an OSGeo project maintained by the OpenLayers Developer Team. It is still under development in these days. The two well-known and widely used branches of this project are OpenLayers 2 and OpenLayers 3. The third version was officially released this year (August, 2014.), and OpenLayers 3.1 has been announced. This also means, that OpenLayers 2 got out of development and the current version is its final form. OpenLayers 3 on the other hand is under constant development, so applications written with it may require frequent maintenance. In return we will get an interface armed with the capability of using up-to-date formats (e.g. TopoJSON), having beautifully rendered maps (WebGL) or in the future providing 3D maps (based on Cesium).

Web mapping interfaces

When you start to develop your web GIS application, the first consideration will be the the interface you wish to work with. There is a wide range of open source GUIs. There are a lot of similarities in them, like they are written in JavaScript (the library which you will use to publish your maps if not the whole software), they use similar sets of values, they use similar methods to reach servers or handle geospatial data. There are lot of comparisons between various GUIs, but in reality there isn't such a thing like best and worst interfaces. Well, maybe there are worse ones, but I won't write about all of them. I will show some of the most popular ones, without attempting to be comprehensive. This post will be a prelude to using these interfaces, showing general considerations and methods to use them.