The React team has been working on an improved rendering engine called Fiber. This is an oversimplification but Fiber essentially breaks down per-frame renderin

The React team has been working on an improved rendering engine called Fiber. This is an oversimplification but Fiber essentially breaks down per-frame rendering into several sub rendering tasks, allowing for smarter multi-threading (in the case of web workers) and even single threading (the renderer now returns control of the main thread much faster and more frequently, allowing for more opportunities to do GC and other operations without as much of a negative effect.) An example of Fiber in action is here: https://www.youtube.com/watch?v=Qu_6ItnlDQg https://www.youtube.com/watch?v=Qu_6ItnlDQg What this amounts to for React developers is the introduction of explicit priority rendering, which can be very useful in VR environments. So for example, updates to your UI from external processes (such as an XHR) can be set to lower priority than updates to the hand model that's controlled by the controllers.