bevyengine/bevy

Bevy is an open-source game engine written in Rust designed to make building games feel simple while still being powerful enough for serious projects. It targets both 2D and 3D game development and aims to give developers fast compile times and high runtime performance, two things that are often in tension with each other in game development. The central design philosophy is "data-driven" development using a pattern called ECS (Entity Component System). Instead of organizing your game around objects that contain both data and behavior, ECS separates them. Entities are just unique identifiers, think of them like game objects without any properties of their own. Components are plain data structures attached to entities (for example, a Position component, a Health component, a Sprite component). Systems are functions that run on all entities that have certain components, for example, a movement system that processes every entity which has both a Position and a Velocity component. This separation makes it easy to parallelize game logic across CPU cores, because the engine can figure out which systems are independent and run them simultaneously. Bevy is also modular: everything is a plugin, including features like rendering, audio, input handling, and even the main loop. You start with a minimal core and add only what your game needs. The default plugins give you a window, a 2D/3D renderer, asset loading, and common input handling out of the box. A game developer would use Bevy when they want to build games in Rust, enjoying the language's memory safety guarantees and performance, without needing to write an engine from scratch. It is well-suited to indie developers and hobbyists who value open-source tooling and fast iteration. The tech stack is Rust, distributed as a Cargo crate. It supports Windows, macOS, Linux, and WebAssembly (running in a browser).