Scrivener - Scrivener is a content-generation tool for composing and structuring documents.
Novelize - Novelize is an online novel writing app designed to keep authors on track.
Celtx - Celtx is a scriptwriting software platform with applications in a wide range of mediums but that specializes in helping screenwriters.
Manuskript - Open-source tool for writers.
Trelby - The free, multiplatform, feature-rich screenwriting program!
BlankPage - Stay motivated to write, and finish your story