The Open Source Geospatial Foundation, founded in 2005, is a not-for-profit organization whose mission is to support and promote the collaborative development of open geospatial technologies and data. The foundation provides financial, organizational and legal support to the broader open source geospatial community.

OSGeo official website: http://www.osgeo.org/

See also:

• Planet OSGeo - follow OSGeo bloggers
• Service providers - find commercial support
• Mailing lists