It's a multi threaded,3-D simulation engine with a modular event based parallel architecture in the making. It is a personal project of mine and am completely building it from scratch.
http://www.gamasutra.com/blogs/MichaelKissner/20151027/257369/Writing_a_Game_Engine_from_Scratch__Part_1_Messaging.php http://thegamecharacter.blogspot.com/ (My own old blogpost about an attemt i did way back)