John August has also talked about using plain text for movie/television screenplays, specifying a format based on markdown and hollywood standard: https://fountain.io/

Sharing aside, I imagine a plain text format would also be helpful for version control.

Haha, yes, as I was finishing writing the parser, I stumbled upon Fountain and realized my genius idea for a markdown based playwriting format was not so original. Ended up adding some Fountain syntax to my parser and ultimately I built a very functional but not feature complete implementation of Fountain by accident.

I built sharing and (sort of) versioning into the web app. Everything is saved in localStorage and on a MySQL server. You can Save or Save As, and every time you Save As it inserts a new database row and gives you a new, sharable URL.

I wanted an experience where you didn't have to login to use it, but ultimately, having a way to keep track of all those URLs would actually be a pretty decent versioning system--add diff checking between script versions and you end up with something pretty handy.