Another terminal-based slide presentation tool. This one seems nice in that it simply uses markdown and every horizontal rule marks a new slide. Simple, efficient, nice.

Also has a simple guide on how to export slides to pdf on the page.

Terminal slide presentations. Uses its own markup language (unfortunately) but by doing so comes with some nice features such as emulating a shell command or even typing it with animation.

Very simple, basic functionality slide software. Has a couple of ..interesting features like

Slides with exuberant amount of lines or characters produce rendering glitches intentionally to prevent you from holding bad presentations.

but in general seems quite nice

Hold presentations with a projector connected (i.e. dual-screen) - you get to read notes you prepared and see the current and upcoming slide in a little side-window while the big screen just sees the current slide.
I think slide.js/reveal.js has a similar feature that can be activated with a key combination but this has it baked in

Don't just present; interact with your audience!

reveal.js on steroids! Get beautiful reveal.js presentations from any Markdown file - webpro

A beginner's guide to building HTML

Create 'powerpoint' presentations directly from a markdown file in git-(lab/hub/gitea/gogs)