Final Draft is described as 'Use your creative energy to focus on the content; let Final Draft take care of the style. Final Draft is the number-one selling word processor specifically designed for writing movie scripts, television episodics and stage plays' and is a Novel Authoring tool in the news & books category. There are more than 50 alternatives to Final Draft for a variety of platforms, including Windows, Mac, Web-based, iPhone and iPad apps. The best Final Draft alternative is Scrivener. It's not free, so if you're looking for a free alternative, you could try Manuskript or Story Architect (STARC). Other great apps like Final Draft are Fade In, Hemingway Editor, yWriter and Untold Novel.
SO intuitive, real-time collaboration, integrated outliner, unlimited revision tracking, access from anywhere, online and offline writing, perfectly standard (can't tell the difference from a Final Draft PDF), compatible with basically all filetypes, and my favorite thing: see full line history and all line comments in one click, next to every line.