Scrivener - Scrivener is a content-generation tool for composing and structuring documents.
Dabble Writer - Writing software for novelists.
Final Draft - Use your creative energy to focus on the content; let Final Draft take care of the style.
Novlr - Online word processor and organizer for novel writing.
Manuskript - Open-source tool for writers.
Novelize - Novelize is an online novel writing app designed to keep authors on track.