NinjaBuild Engine\Extras\ThirdPartyNotUE\ninja-build\ninja.exe Ninja is a small build system with a focus on speed. It differs from other build systems in two major respects: it is designed to have its input files generated by a higher-level build system, and it is designed to run builds as fast as possible. https://github.com/ninja-build/ninja/blob/master/COPYING Licencees P4 /Engine/Source/ThirdParty/Licenses