I think the most important but often overlooked aspect of the adoption of Markdown is how plain text has made a comeback. There are many Markdown variation and flavors. Most are still used for Markdown’s original purpose—turning text into HTML. But one project has built on the idea of markdown and is using plain text to fill a different need. The Fountain project has created a plain text format that is designed for print (or PDF).
I do all my writing in Ulysses. I also like to keep all of my files in its library. Since I started using it, the idea of having individual files scattered about my computer is just plain barbaric. The cost of this trade off is that if Ulysses doesn’t support a feature, I have to add raw HTML into the files. Normally this isn’t much of a problem. A bit HTML set off with ~~ isn’t distracting.