Ninja Framework

Ninja is a small, incredibly fast build system designed specifically to automate the compilation of large C++ and C projects. Instead of being written by hand, Ninja files are generated by higher-level meta-build systems like CMake.

Ninja achieves its high speed by utilizing a lazy evaluation approach and building a precise dependency graph to execute only the necessary commands. It is optimized to evaluate complex rules and execute thousands of file-write operations in milliseconds.

Ninja files are typically generated automatically by build tools, but you can write them manually using a straightforward syntax of variables, rules, and build statements. A typical manual script involves defining a compiler rule and a "build edge" that links objects into an executable.

While it is technically possible to execute arbitrary shell commands, Ninja was explicitly designed to meet the demands of compiling large native codebases like Google Chrome. It is rarely used for Java or Python projects, which typically rely on their own dedicated build systems.