I do not know these guys and gals personally but they seem the crowd that you want to have over for drinks.
The good guys:
"The Open Source Geospatial Foundation, or OSGeo, is a not-for-profit organization whose mission is to support and promote the collaborative development of open geospatial technologies and data."
A collection of tools and links to open source geo-stuff. Comes with helpful descriptions. *Beware of some faulty or broken links. If you encounter this problem, usually "google"-ing the link will bring you to the correct site.*