yWriter - Free writing software designed by the author of the Hal Spacejock and Hal Junior series. yWriter6 helps you write a book by organising chapters, scenes, characters and locations in an easy-to-use interface.
Writer's Cafè - Write a novel or screenplay with Writer's Cafe: a powerful but fun writer's environment that includes the StoryLines structuring tool, a notebook, journal, writing quotations, scrapbook organiser, a 60-page e-book and more.
Manuskript - Open-source tool for writers.
Scrivener - Scrivener is a content-generation tool for composing and structuring documents.
Twine - Twine is an open-source tool for telling interactive, nonlinear stories.
Story Architect (STARC) - STARC - A smooth yet powerful screenwriting experience for devoted authors. With only wanted features and simple workflow it runs faster than all your previous apps combined.