SanderMertens/flecs

Health v2 · maintenance only

Flags: no_license

Adoption not part of the score

8619 stars · 615 forks observed · 2026-08-28

What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-29, confidence not recorded

Flecs is a fast, lightweight Entity Component System (ECS) framework for C99 and C++17 that enables building games and simulations with millions of entities. It features an archetype/SoA storage, entity relationships, prefabs, hierarchies, a query language, and a lockless multithreaded scheduler.

Use cases

• build a game engine with an entity component system architecture
• simulate millions of entities efficiently
• manage entity relationships and hierarchies in a game
• run game logic in parallel across CPU cores
• serialize game state to JSON with reflection
• write data-oriented gameplay systems with queries

When to choose

• you need a production-ready, zero-dependency ECS for C or C++
• you want high-performance archetype-based storage for large entity counts
• you need entity relationships, prefabs, or hierarchies in an ECS
• you want to run systems in parallel on multiple cores
• you target multiple platforms including the browser via emscripten

When to avoid

• you need a full game engine with rendering, audio, and physics built in
• your project is small enough that an ECS adds unnecessary complexity
• you require a garbage-collected language binding as your primary workflow
• you need an ECS with a large plugin ecosystem beyond the core framework

Facets

framework · maturity stable

game-engine simulation serialization concurrency simulation cross-platform cpp c wasm ecs entity-component-system data-oriented-design c99 cpp17 no-dependencies archetype-storage entity-relationships prefabs multithreading game-development gamedev

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