What is "NativeScript" exactly and are users able to use it without downloading additional suff?

[system]

	Attention	Topic was automatically imported from the old Question2Answer platform.
	Asked By	Joe0239
	Old Version	Published before Godot 3 was released.

This is what I am talking about

[system]

	Reply From:	eons

Here are details about it, this post is about an earlier implementation and some things may have changed:

GDNative is here!