PolyGlot – Chessprogramming wiki

Polyglot is open source, licensed under the GPL, and is able to run on various operating systems, which allows to run UCI engines not only under Windows with its native chess GUIs, but also under Linux and Mac OS using XBoard. PolyGlot 1.4 provides a simplistic opening book implementation, referred as bin-opening book format.

https://www.chessprogramming.org/PolyGlot