QGIS is the main mapping software used by Windrose GIS Consulting. It is a desktop application, a geospatial data browsing application, and a geospatial data web server. The applications are maintained by programmers and geographers from all over the world and guided by Board and Project Steering Committee that ensures that the software will continue to be on the cutting edge. Further, python plugins add to the core application and allow for specific needs to be met.
PostGIS is a spatial extension of the PostgreSQL relational database. It is the backend database for concurrent editing and storage of data. It also has an expansive suite of geospatial functions that can be used within SQL queries to arrive at answers to geospatial questions. The project is overseen by the OSGeo Foundation and continues to provide great geospatial functions coupled with the security of PostgreSQL.
SpatiaLite is a file based geospatial data extension built on top of the SQLite file based database. It is a great tool for sharing data while keeping it well organized and the amount of files to a minimum. It is also useful for field collection of data and works with mobile applications and PostGIS to keep data synced. The project is maintained by GAIA-SINS federated projects.