> Reimplement in the way that they change certain rules to accommodate a more "modern JS" feel What exactly do you mean by this? > And they absolutely use TS

> Reimplement in the way that they change certain rules to accommodate a more "modern JS" feel What exactly do you mean by this? > And they absolutely use TS for the std library, just not in the runtime itself Yes, internally. The code that actually makes up deno itself is just plain Javascript.