geOrchestra is a free, modular and interoperable Spatial Data Infrastructure software born in 2009 to meet the requirements of the INSPIRE directive in Europe. geOrchestra’s core features a security proxy and a single-sign-on authentication system. Next to this core are independant and interoperable modules to build your own Spatial Data Infrastructure: - a metadata catalog based on GeoNetwork, - a map and features server: GeoServer, - a map tile server: GeoWebCache, - an advanced web map viewer, - a data extractor, - and several other admin-oriented modules. Modules interact using OGC interfaces or REST APIs. Initially covering Brittany, then France, geOrchestra now spreads worldwide with SDIs in Bolivia, Nicaragua, Switzerland and India. http://www.georchestra.org/