Impressive is a program that displays presentation slides using OpenGL.
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. Some of them are:

 * Overview screen<br /> * Highlight boxes<br /> * Spotlight effect<br /> * Presentation scripting and customization<br /><br /><br />read more <a target="_blank" href="">here</a><br />