Prezi-like web interface. Flash or HTML5?

Question

I would like to write a web interface that resembles Prezi.com in its user experience. What would be the best technology for that purpose?

Project requirements:

1. Fast implementation (it is a demo) - I'd appreciate a rough estimate
2. Large amounts of data - dynamic content loading/unloading is required.

My natural candidates are Flash and HTML5.

Prezi.com is an alternative platform for presentations that uses single canvas zoom/pan/rotate controls instead of classic slide-by-slide interface. An example is available here.

Edit

The visual part of my website needs to display multiple widgets (images, videos, text) on canvas and allow the user to navigate by zooming and panning. Each widget would have its own native zoom. The number of widgets would be enormous, however, simultaneously only a small number of widgets are visible.

Answer 1

If it still matters to you, Webpgr is exactly what your are looking for. It's HTML5 based and you can use click and swipe gestures to navigate through the page. There is a Photoshop-like online editor. It's in beta but you can request an account.