Windows only: Q10 is a full-screen text editor with a minimal interface, which isn't all that new. But it also supports the best features of heftier editors, like text substitution, custom text counters and alarms, and personalised auto-correct and spell check.
If you've got a word or character goal to reach, Q10 shows that goal as a percentage at bottom, along with other statistics that update as you type. If you've got specific layouts and margins to stick to, or a particular method of calculating your line counts, Q10 has you covered. You can save notes, create snippets of text to expand when needed, change the settings for your screen colours, auto-saving and other parameters.
Honestly, though? A certain Lifehacker editor found the default typewriter key press and carriage return sounds (clack, clack, clack, ching) oddly soothing and motivating. No doubt they might get old to the user and definitely the people around that user if headphones aren't used, but there's something very persuasive about the percussive rhythm of hearing yourself type. You can, of course, turn them off or replace them with something like the Super Mario sounds found at Q10's home page.
Q10 is a free download for Windows systems only and can be run as a no-install portable application. Thanks Maravilha!