GeneWeb

GeneWeb is a free multi-platform genealogy software tool created and owned by Daniel de Rauglaudre of INRIA. GeneWeb is accessed by a Web browser, either off-line or as a server in a Web environment. It uses very efficient techniques of relationship and consanguinity computing, developed in collaboration with Didier Rémy, research director at INRIA. GeneWeb is used as the engine for several public genealogy websites, including Geneanet, a collection of inter-searchable genealogical databases currently containing references to more than 225 million persons.

Excerpt from Wikipedia: GeneWeb. Content available under CC-BY-SA 4.0.