QGIS is the most popular and used Geographical Free Open Source software in the whole world, growing fast and being a serious competitor to the near monopolistic proprietary alternative.
QGIS is born in 2002 thanks to Gary Sherman that was looking for a simple way to visualize geospatial data stored in a PostgreSQL/PostGIS database. In the following years more people got involved in the project and QGIS stared to become a complete GIS software with support for both vector and raster data. During these 18 years more and more people developed specialized geospatial algorithm to extract information from the data and to provide a simple interface for the end user. Different milestones have been reached, e.g. the support for thirdly part software, like GRASS, SAGA, Orfeo Toolbox and R; a Python interface has been added so that it is easy to develop new spatial algorithms as *plugins*. Thanks to these features QGIS quickly became popular and widespread. Public administration, private companies, Universities and GIS expert use QGIS and are investing resources back to the project.
The success of QGIS is due not only to work of developers and the resulting powerful and easy functions, but also to the strong community behind the software: document writers, translators participate not only *building* QGIS as a software but by growing QGIS as a **community**.