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.
Free Online & Cloud-Based Apps
Afterwriting: A web-based Fountain editor. It also has FDX conversion.
Writer Duet: Has a free version that limits you to three docs. Supports writing and exporting in Fountain format.
Fountainize for Google Docs: A free add-on that lets you write in Fountain inside Google Docs The free version is limited to 800 elements, but it’s great for drafts and collaboration.
Fade In also allows you to export .fountain files and has a limited-feature free version.
Fountain.io has a full list of supported applications, and you can learn more about Fountain in general here.
Using Final Draft? Learn a sneaky way to get a .fountain file from your Final Draft scripts.