Scrivener, as its designers describe it, is "a word processor and project management tool created specifically for writers of long texts." It is available for download here. After the thirty day free trial period, it costs forty dollars to buy the license for continued use. I've been using it for a few days now and am thrilled. The best feature is a virtual corkboard that allows you to create and rearrange index cards, displayed all at once--the perfect tool for developing and plotting story events. You can open research files alongside your text draft, view synopses of each chapter, and keep track of the status of each chapter or scene. Although I haven't actually done it yet (I'm still in the plotting stage), you can supposedly view different threads in a document, for example calling up all the scenes in which a certain character appears, or that take place in a specific setting--an amazing tool for following the execution of story arcs and checking a draft for consistency. I'm not particularly computer savvy and I'm finding Scrivener easy to use. The documentation is pretty straightforward and there is a good tutorial to learn with. (Okay, I do have an incredibly helpful scientist husband to help me when I get stuck, but I'm sure you'll be fine without him.)
Those of you who write on Mac computers might want to check it out (you can import already existing work into the program). If my experience so far is any indication, Scrivener is worth every penny of the licensing fee. (Disclaimer: I am in no way associated with or compensated by the software designer, just a happy customer.)
I'll keep you updated on how it goes as I use more of Scrivener's features. And if anyone has other writing software to tout (even if it's for the PC), please feel free to tell us about it.