What technology was used to implement this Rich Web UI?

In another question, someone mentioned this site which b开发者_JAVA百科lew me away: http://zoomii.com

Does anyone know how they implemented this rich UI? At first I thought it was Flash but I don't see the Flash context menu. Did they hide the context menu somehow or is it some other rich web UI technology?

---

Javascript, specifically, this javascript.

---

Microsoft has the similar technical via silverlight or javascript:

http://silverlight.net/learn/quickstarts/deepzoom/

http://weblogs.asp.net/bleroy/archive/2008/11/20/deep-zoom-without-silverlight.aspx

It is really cool.

---

It's made with javascript.

---

It wasn't really minified, in that using Firebug you can read it, though the beginning part is unreadable. It is 17600 lines of javascript using html for this page.

It would be helpful if they had taken some steps to reduce the file size, but it is a slick example of DHTML.