I know this is ridiculous, and it’s undoubtedly been done before and well. But, I had fun doing this, so leave me alone.
Welcome to ImpotentPoint. The site explains the markup, but basically you begin a new slide by beginning a line with four or more dashes. A line that begins with a = is taken as a head (<h1>). You can use up to six =’s to get six levels of heads. A bullet point begins with a *. A bullet point that will build begins with a +. Unfortunately, you have to use HTML markup to get a graphic in. And that’s about it.
I like the idea of writing slides in plain text, but I’m afraid that the markup required to make this actually useful would turn out to be as complex as just writing them in html.
If you want to see a tutorial click on this button and paste the text into the first text box at ImpotentPoint.