EnTT
A fast and reliable entity component system (ECS) and much more
...Among others, it's used in Minecraft by Mojang, the ArcGIS Runtime SDKs by Esri and the amazing Ragdoll. The entity-component-system (also known as ECS) is an architectural pattern used mostly in game development. This project started off as a pure entity-component system. Over time the codebase has grown as more and more classes and functionalities were added. Statically generated integer identifiers for types (assigned either at compile-time or at runtime). A constexpr utility for human readable resource names. An incredibly fast entity-component system based on sparse sets, with its own pay for what you use policy to adjust performance and memory usage according to the users' requirements. ...