Last night the Oxford/London IF Meetup had a session on three tools, and I promised to write up some notes for the benefit of the people who weren’t able to attend.
inkle’s ink, the open-source, Unity-compatible language used by inkle for 80 Days and other projects. If you’re curious about ink and missed the session, there’s always Joe Humfrey’s GDC talk on the subject; but Jon also talked to us about The Intercept, the new free and open source ink/Unity game.

Jon was a bit apologetic about the fact that there is currently no specialist ink runner, meaning that if you want to create (say) an ink entry to IF Comp, you will need to use Unity to build standalone apps. But to me, this is also partly a selling point, in the sense that ink is designed to build custom, professional-looking apps and doesn’t constrain the author to something a bit bland.
Doing this doesn’t have to mean figuring everything out from scratch. What I hadn’t realized about The Intercept until that conversation — and it’s very useful to know — is that the whole Unity project is open-source, not just the ink script that goes into the game. This means that if you want to build an ink/Unity game of your own but you have very little Unity experience, you could download the whole thing and then copy or gradually adapt The Intercept‘s look and feel. (Also worth saying: a personal Unity license is free if you’re not making significant money from your projects.)
Edited to add: on Twitter, I learned about the existence of Blot, a rough and ready alternative Unity project using ink that has fewer genre-specific features than The Intercept. So you have options, even!
Personally I’ve found working with an existing Unity project to mod it into something of my own to be a great route into learning how Unity works, because it means I don’t have to tackle understanding every type of asset at once. So if you’re in the same boat, that might be a way to get an ink game functioning, and then later you could start to figure out things like changing the fonts and presentation. (If you want to! Because it’s open source, you could just keep the way it looks, too.)
Indeed, you may want to play The Intercept even if you have no interest in using ink yourself: it is a short piece, short enough to play through (if not necessarily win) in 5-10 minutes, and it makes interesting use of the conversational options, as in the above example. Especially early in the game, we’re offered the chance to lie without really knowing ourselves what the truth is; and I found myself hesitating over whether I wanted to take the course that seemed safest or whether I wanted to steer towards the option that might reveal most about the story. Did I trust the protagonist, or not?

Disclosure: this review is part of the IF Comp review exchange. J.J. Gadd was 
Lifeline: Silent Night