OSE France is a french no profit association working on researching and developing the GVCS.
you can find the French website and all the documentation from the French team here:
the Solar Concentrator: Technical requirements English version: http://wiki.osefrance.org/doku.php?id=wiki:technical_requirements_english or http://opensourceecology.org/wiki/Solar_Concentrator/Research_Development
Technical requirement French version: ...
Status: Prototype in scale completed and documented. in French (BOM, costs, assembly instructions, studies): http://wiki.osefrance.org/doku.php?id=wiki:demonstrateur in English on instructables: http://www.instructables.com/id/Solar-OSE-Solar-concentrator-for-steam-generation/
New functional requirements for the 1:1 size is currently being developed and discussed here: http://forum.osefrance.org/viewtopic.php?f=2&t=3019