In the author's defense - this is probably a prototype, hacked together without trying to optimize performance. You should not judge the idea by its realization's performance at this point in time.
It is true that I plan a custom renderer with scripting support, to replace the HTML version. From the tests I performed by now, it can be smoother and faster than the current version. But it is yet to be seen how well would a substitution to HTML catch up with the current state of art CSS+HTML+JS.
At some moment I had a version with cached bitmaps that simply flew fast and smooth. But, since HTML has some serious issues with rendering to bitmap from js, I had to pick the slower version with native real time HTML rendering.
