Free Writing Software:
yWriter – This software allows you to create chapters and scenes. For Windows, but will also run on GNU/Linux and Mac OS X using Mono 2.4 (or later)
FocusWriter – Distraction free writing. Linux, Windows, and Mac.
StoryBox – Scenes, chapters, locations, full screen typing mode.
Liquid Story Binder XE – Last updated in 2011. Offers a great deal of flexibility with lists, builders, planners, timelines, and so much more. For Windows.
Scrivener – Mac and Windows versions. Notes, outlines, and multiple views.
WriteWay – Notes, character profiles, research folders, and synopsis to help organize your novel information.
Storyist – Mac and iPad only. Word processor, storyboard, outlining.
Aeon Timeline – For Mac (Windows version in the works). This looks like an outlining software.
Online Sites with Free or Paid Versions:
Write or Die – Free online or paid desktop version (works with Mac, Windows, and Linux, also iPad). If you need a bit of prodding to write, this gives you consequences from gentle reminders to erasing what you’ve written if you pause too long.
Yarny – Write in the cloud. Monthly subscription. I haven’t tried this one, so you’ll have to check it out to see everything they offer.
Pangurpad – Online writing tools plus an online community. You can register for a free account. I haven’t used this either, so once again, check it out if it sounds interesting.
Free Online Office Software: