Byword is a full-screen, "distraction-free" word processor that has an interesting twist: it focuses on just the text around your cursor (or even just the current line), dimming the rest of your composition so that even that can't distract you. Byword (and its predecessors) are based on the idea that you'll be at the top of your writing game if there's nothing else on your screen. Whether you subscribe to that theory or not, it's becoming an increasingly crowded field. Thankfully, there's more to Byword than just a blank screen and blinking caret.
Byword, which can also run in a windowed (non-fullscreen) mode, brings great typography along with its minimalist interface. Some of its brethren, like OmmWriter Dana, have done this as well, but if you add in excellent keyboard navigation, hyphenation support and its unique focus mode, Byword begins to stand on its own.
Oh, one more thing. While I don't personally subscribe to the distraction-free idea, Byword has added one thing that always gets my attention in any writing environment: Markdown support. MultiMarkdown support, actually, with footnotes, tables and other fun stuff. Wondering what I'm talking about? Have a look at TUAW's Markdown Primer and the MultiMarkdown documentation for more advanced features. Use Markdown syntax while you're writing, then flip over to the Markdown Preview to see your rendered text. The preview mode has buttons for copying HTML source (great for pasting into blogs) and for exporting the HTML to a file (optionally including the Byword visual styling).
Markdown is a great move for Byword. I'm seeing increasing support for this popular format across the board, which I think is a great thing. I do wish for a few things, including my usual plea for advanced editing tools, such as auto-pairing of brackets and automatic list continuation. I would also love to see an option for printing the rendered document directly from Byword. You could print straight to PDF that way, too.
If you want a good-looking editor for plain text or minimal rich text and don't want all of the extra buttons and formatting options, this is worth a peek. There's a free trial available on the Byword homepage, and you can pick up Byword on the Mac App Store for US $9.99.