It's not one that seems to get much publicity, and one I downloaded from a random website thinking it was just another engine. As of yet, it hasn't been beaten at all in my own engine tournaments and has even managed to beat Stockfish 11 and the latest Stockfish development version. It will also wipe the floor with any older Stockfish version or any non-Stockfish engine.
Based on this thread, my interpretation/opinion is that it's an illegal fork of Stockfish and maybe other top engines (no source code available). Whether that's an important distinction is up to you.
http://talkchess.com/forum3/viewtopic.php?f=2&t=69352
It's not one that seems to get much publicity, and one I downloaded from a random website thinking it was just another engine. As of yet, it hasn't been beaten at all in my own engine tournaments and has even managed to beat Stockfish 11 and the latest Stockfish development version. It will also wipe the floor with any older Stockfish version or any non-Stockfish engine.