Smashcut requires all writing assignments to be published in .Fountain — a plaintext markup language for standard screenplay formatting. It is a light-weight and an open-source format that is an industry standard nowadays.
Using Final Draft? Learn a sneaky way to get a .fountain file from your Final Draft scripts.
Fountain.io has a full list of supported applications, and you can learn more about Fountain in general here.
Our current favorite screenwriting program is Writer Duet, which allows you to create three scripts for free, but has amazing features if you decide to upgrade to the paid version.
Fade In also allows you to export .fountain files and has a limited-feature free version.
If you're looking for a totally free option, check out Trelby (for linux and windows only at the moment).