Ninja is a build system developed by Evan Martin,[4] a Google employee.

[5] In essence, Ninja is meant to replace Make, which is slow when performing incremental (or no-op) builds.

[6] This can considerably slow down developers working on large projects, such as Google Chrome which compiles 40,000 input files into a single executable.

In fact, Google Chrome is a main user and motivation for Ninja.

[7] It's also used to build Android (via Makefile translation by Kati),[8] and is used by most developers working on LLVM.