Disclaimer: Despite being very similar in the end goal, This project doesn't compete with this awesome one. The flutter engine itself doesn't know how to deal with desktop platforms (eg handling mouse/keyboard input). Instead, it exposes an abstraction layer for whatever platform to implement. The purpose of this project is to implement Flutter's Embedding API using a SINGLE code base that runs on Windows, MacOS, and Linux. GLFW fits the job because it provides the right abstractions over the OpenGL's Buffer/Mouse/Keyboard for each platform.