I collect here realisations of ECS in Godot. I looke at them form Game Mechanics point of view.

Godex. https://github.com/GodotECS/godex I don’t like it use Node2d for Entity. may be it is perfomance issue i will back to it late.

GodotECS. https://github.com/baiXfeng/godot-ecs Looks good, but it is GDScript and it is not using Godot Node and Editor features.

Godot Bevy. https://github.com/jrockett6/bevy_godot4 Look interesting, but hard to install and change. I will back to it late when i will understand what featues i crusial needed.

Not Godot ECS.

https://github.com/SanderMertens/flecs this one inspairing me very much. I found here a lot of features i thought about.

https://github.com/skypjack/entt one of the famosts ECS in C++.