"Double-O" is a new MVC theme architecture that runs on top of WordPress and promises to completely revolutionise both your WordPress programming and theme development.
It's structured, configurable, extensible, and supports a revolutionary Model/View architecture, plus a powerful templating language that offers total (or partial – it's up to you) separation of presentation and logic.
Not only that but it's been designed from scratch following best practices and modern techniques, leveraging the best of PHP5 to eliminate the common WordPress hacks and workarounds you've come to take for granted.
If you're a seasoned developer working with real MVC frameworks, this is what you've been waiting for. If you're a WordPress stalwart, or more of a hobby programmer, welcome to a wonderful new world.
It's currently in Beta, and will be launching sometime before the end of 2013. To take part in the Beta test, sign up here.