Ya, I didn't even know marp existed before i started working on it. But Deckless has its own opinionated way of rendering markdown, but the basic principles are the same... just turn markdown into something presentable. Maybe I can incorporate marp's custom markdown design hints such as background properties etc in the future? But it's really just meant to do everything out of the box without any customization besides your markdown.

Also main difference is that it's just a web tool so it works with a UI on the browser and supposed to be simple to use for anyone.