Presentation software. Windows has Power Point, Apple has Keynote, and Linux has Open Office. Everyone hates presentation software and everyone uses it. If you’re someone who works on multiple platforms, you might have to learn to use two or more of them.
Unless, that is, you’re an Emacs user1. In that case, you can learn how to use Beamer with Org mode and take it with you wherever you go. If you want animated slides with lots of gee whiz features, Beamer probably isn’t for you but if you want to make nice looking slides for a talk or other presentation, it’s easy, portable, and free. You don’t have to worry about the machine that will be projecting the slides since the output is PDF and any PDF projector software will do.
Over at the Worg Site they have a very nice tutorial on generating Beamer slides from Org mode. Even if you don’t know LaTeX or Beamer, you can still generate nice slides directly in Emacs. If you find yourself having to put together slides for a talk, it’s worth taking a look at the tutorial. It’s not too long and afterwards you’ll be able to generate slides on any platform that supports Emacs and LaTeX.
UPDATE: Eric S. Fraga, who authored the Worg tutorial I linked above, writes to point out that there’s a newer tutorial by Suvayu Ali that covers the new(er) exporter.
Footnotes:
Or you know LaTeX/TeX sufficiently well to use Beamer directly.