We started out as slid.es and then bought slides.com. I won’t share the exact amount, but I believe it was 5x our yearly revenue at the time so safe to say it was a big investment. We haven’t raised any money so my co-founder and I had to pay out of pocket.
Hey! I’m the creator of reveal.js. Thanks for sharing. Happy to answer questions if you have any.
reveal.js was first released in 2011. A few years later I also launched a visual editing environment for reveal.js called Slides (slides.com). It has some pretty unique features targeted at developers, like a built-in CSS editor, access to the HTML source, and stepped line-by-line code highlighting. http://slides.com/news/developers
It’s been really great finding a sustainable way to continue working on open source (reveal.js) thanks to the revenue from the proprietary editor (Slides).