Dirk Riehle provides an excellent explanation of business behind Open and Closed Source Software: http://www.riehle.org/computer-science/research/2007/computer-2007-article.html.
LISASoft/TerraPages apply these Open Source business principles to Geospatial Software. LISASoft provide value using Open Source Geospatial Software.
Many Open Source Geospatial Products offer equivalent functionality and quality to existing dominant Closed Source products. Initial costly development is complete and Open Source offers better value for money.