Rodovid

[2][3] It provides a web service built using MediaWiki and its own Rodovid Engine software to help store and visualize family relationships.

[4][5] Rodovid was founded in September 2005 by a group of developers and genealogy enthusiasts in Kyiv, Ukraine.

[2] As of January 2019, Rodovid had over 1,055,000 total records for individuals across all languages, including over 590,000 in Ukrainian and Russian.

It seems that Rodovid is the largest genealogy website under a free license and accessible without restriction.

[12] The Rodovid project's data and descriptions are stored on servers in Kyiv, and available under the Creative Commons Attribution license where not already in the public domain.