Prezi - Welcome to Prezi, the presentation software that uses motion, zoom, and spatial relationships to bring your ideas to life and make you a great presenter.
SlideShare - Discover, Share, and Present presentations and infographics with the world’s largest professional content sharing community.
Slidebean - Presentations that design themselves
Ludus - Limitless creativity for your slides.
ShareBoost - Beautiful and simple Coming Soon websites, without coding
ZapTheater - Presentation software to make your slideshow autoplay on the Internet, replacement for Powerpoint