Preface

We live in the century of information and a lot of this information is susceptible to being represented geographically. This is probably the main feature that has made Geographic Information System (GIS) become one of the most important aspects of many companies. GIS-related technologies are a growing industry and, because of this, GIS has become a desired skill for many professionals.

The universality of the Web and the improvement on the browsers' performance has made it possible for the Web to become a main part of the current GIS and has subtracted the importance of desktop applications because of its capabilities: the browsers allow us to show data visualizations to the masses, create online data editors, and so on.

Nowadays, OpenLayers is the most complete and powerful open source JavaScript library to create any kind of web mapping application. In addition to offering a great set of components, such as maps, layers, or controls, OpenLayers offers access to a great number of data sources using many different data formats, implements many standards from Open Geospatial Consortium (OGC, http://www.opengeospatial.org), and is compatible with almost all browsers.