Specs is an Entity-Component System library written in Rust. Unlike most other ECS libraries out there, it provides * easy parallelism * high flexibility * contains 5 different storages for components, which can be extended by the user * it's types are mostly not coupled, so you can easily write some part yourself and still use Specs * `System`s may read from and write to components and resources, can depend on each other and you can use barriers to force several stages in system execution * high performance for real-world applications