Open Source
The OSGeo is not a primary source of information regarding Free Software or Open Source. Please refer to the corresponding web sites for a thorough treatment. This page intends to give a quick insight to the topic and explain some basics. Feel free to edit this page if you feel that it is not enough or needs pruning.
Introduction
Open Source is a public, collaborative development methodology that promotes early publishing and frequent releases. It allows users to study, change, and improve the software, and to redistribute it in modified or unmodified form. Read the Open Source Definition to learn about the details.
http://www.opensource.org/trademarks/opensource/web/opensource-110x95.png
Open Source is closely related (and sometimes even percepted as identical) to Free Software.
Commercial Use of Open Source Software
Open Source Software is not an opposite to commercial activities! There are many companies and individuals who make a living by producing, maintaining and enhancing Open Source Software or by offering all kinds of services around it. In the geospatial realm it has grown into a healthy Business ecology.