E4X produces a standalone (pure markup) mutable XML node tree intended to encode data for cross-platform communication and data exchange.
JSX produces an non-standalone (links to JS symbols, functions, etc.) node tree intended to encode DOM fragments for UI updates.
E4X is not needed today, because we use JSON for data exchange. So E4X is now simply... JS objects.
E4X produces a standalone (pure markup) mutable XML node tree intended to encode data for cross-platform communication and data exchange.
JSX produces an non-standalone (links to JS symbols, functions, etc.) node tree intended to encode DOM fragments for UI updates.
E4X is not needed today, because we use JSON for data exchange. So E4X is now simply... JS objects.