"Flutter is unique technically because its rendering implementation uses neither WebView nor OEM widgets. Instead, Flutter uses its own high-performance rendering engine to draw widgets."
Factually incorrect since http://www.qt.io/qt-quick/ has done this for a while and has a very mature fast mobile reactive amazing UI engine.
Thanks for the comment. We'll change our FAQ. Issue filed here: https://github.com/flutter/flutter.github.io/issues/55