"Vircadia is the volunteer-run product founded on the open-source code of the original
High Fidelity social VR platform which folded in early 2020" -- https://ryanschultz.com/category/high-fidelity-highlights/
D. Heise, A. Meyer, and S. Strecker. Informatik 2007 --~Informatik trifft Logistik~-- Band 2, volume 110 of Lecture Notes in Informatics, page 48--52. Bonn, Gesellschaft für Informatik e.V., Koellen, (2007)
S. Koch, S. Strecker, and U. Frank. Open Source Systems, Proceedings of The Second International Conference on Open Source Systems, IFIP Working Group 2.13 Foundation on Open Source Software, June 8--10, 2006, Como, Italy, volume 203 of IFIP International Federation for Information Processing Series, Springer, Berlin, (2006)