Jennifer Mack figured out how to use Fountain in Ulysses:
Sadly, Ulysses doesn’t speak fountain as one of its markup styles. But I found a way to fake it.
I wouldn’t recommend Mack’s “Fake Fountain” to anyone new to the syntax. It’s a complete customization and will require a lot of tweaking to go from Ulysses to any other tool that recognizes Fountain. Markup for character names and parentheticals will need to be removed, for example. Through Mack’s custom PDF style, however, you can export a formatted screenplay right from Ulysses.
Since I do almost all of my writing in Ulysses, her point later in her explanation is well taken:
Why bother when I could just use another app like Slugline or Highland? Because I like writing my first drafts in Ulysses and having those drafts in the its document library.[sic] Also users of Ulysses for iPad might find this useful.
The point of Fountain has always been to bring screenwriting into any app. I wish Ulysses had support for Fountain that didn’t require a custom syntax to force it, but it’s nice to know it’s possible.
One note Mack doesn’t mention in her piece. After you create the Fake Fountain markup (or whatever you choose to call it) in Ulysses, you will need to change the document’s markup to recognize the new syntax. To do so, once you’re in a new sheet, go to Edit > Convert Markup > Fake Fountain. From then on all new sheets will have the Fake Fountain markup, so you’ll need to do this again to get back to Markdown, Markdown XL or your preferred syntax.
If you’re a Ulysses user, by the way, I found Mack’s markup through the excellent Ulysses blog. The team at The Soulmen have done a great job of building a community around their app.