...It has been tested in Unity 2020 up until 2020.3.21f1, Unity 2019 up until 2019.2.17f1, Unity 2018 up until 2018.3.13f1, Unity 2017 up until 2017.4f1, and 5.6. The toolkit contains the Mercury messaging framework, which is a messaging and organizational framework built around the Mercury Protocol. Unity organizes its rendered scene objects (known in Unity as GameObjects) using a standard scene graph (known in Unity as the Scene Hierarchy). While Unity is very powerful, it is fairly difficult to achieve nonspatial communication between scriptable components of GameObjects (in Unity, known as MonoBehaviours).