impress.js is a presentation framework based on the power of CSS3 transforms and transitions in modern browsers and inspired by the idea behind prezi.com - an "infinite canvas" for your presentation.
Check out the demo at http://bartaz.github.com/impress.js
Emphasis is placed on design as well as content. The documentation warns that "quite decent HTML and CSS skills", as well as design skills are needed to be able to use impress.js effectively. More Info »
The are however GUIs that help create Impress.js presentations, namely Strut and Impressionist.
* zoom, rotate, scale, 3D perspective
* named slides
* auto-update the browser bar URL
* keyboard navigation
The learning curve is longer than with Reveal.js, and cross-browser support is less extensive.