Impressive is a program that displays presentation slides. But unlike
OpenOffice.org Impress or other similar applications, it does so with
style. Smooth alpha-blended slide transitions are provided for the sake
of eye candy, but in addition to this, Impressive offers some unique
tools that are really useful for presentations.

Creating presentations for Impressive is very simple: You just need to
export a PDF file from your presentation software. This means that you
can create slides in the application of your choice and use Impressive
for displaying them. If your application does not support PDF output,
you can alternatively use a set of pre-rendered image files or you use
Impressive to make a slideshow with your favorite photos.

This requires PyOpenGL, pygame. pdftk is optionally required for
retrieving PDF metadata (page titles, hyperlinks).