EnTT is described as 'Gaming meets modern C++ - a fast and reliable entity-component system (ECS) and much more. EnTT is a header-only, tiny and easy to use library for game programming and much more written in modern C++, mainly known for its innovative entity-component-system (ECS) model' and is an app in the Development category. There are four alternatives to EnTT for Self-Hosted solutions, Windows and Linux. The best alternative is EntityX, which is both free and Open Source. Other great apps like EnTT are Flecs (Free, Open Source), ECSY (Free, Open Source) and Entitas (Free, Open Source).