Looking for a “normal” screenwriting application that will make you forget you aren't using the one you are used to? Trelby is what you are looking for.
Trelby is a free word processor for screenplays, Trelby is an application with all the usual features of a screenwriting application, including a character name database, basic scene reporting, PDF exporting, and more.
Trelby is one of those applications that looks familiar and feels comfortable whether or not you have even opened a screenplay application before. It's exactly what you expect from a screenwriting application; it has all of the essential features and none of the bloat.
Not Closed Source
There are only a few really popular screenwriting applications out there, so some users are very much “married” to the one application they learned in school and will accept nothing in substitute. Trelby (or anything else, for that matter) will not please such a user.
Install Trelby from http://slackbuilds.org.
Trelby truly is an intuitive application. If you have used a word processor, you will feel at home with Trelby.
The advantage to using a dedicated screenwriting application is that all standard formatting is applied automatically for you, with minimal amounts of interaction. Character names are remembered for you and auto-completion simplifies concerns, for instance, about whether you called that day player “Evil Henchman” or just “Henchman”.
Of all the applications in multimedia, screenwriting applications are the least likely to require cross-compatibility. Unless you are collaborating with another writer, you will probably never send out the project file. Since Trelby can export to PDF, it's probably everything you need in a screenwriting application.
On the other hand, Trelby supports two major platforms, and exports to a number of universal formats (including fountain).
Trelby can import Fountain files.