World's First (?) LGPL library for building Mac and iOS Apps from a single Objective-C source base.

I think it's true. Major, non-trivial (full-featured IMGUR client) coming soon to github! Just wrapped the Mac version will be finalizing the iPad version this week. Stay tuned.

Nibitaph - The last framework you'll use for Mac OS X and iPad Development.

If you'd done any amount of Cocoa programming before starting with Cocoa-Touch, your first impression is: how similar these frameworks are.

Your second impression might be "How infuriatingly similar these frameworks are!"

The Nibitaph framework aims to provide, through protocol-oriented programming, a union of AppKit and UIKit that can be used to quickly and easily develop cross-platform (Mac OS X 10.6- and iPad iOS 5.x-) apps.

Home is where the repo is: github.com/genkiyooka/Nibitaph/

Nibitaph is an umbrella consisting of the following submodules:
github.com/genkiyooka/WithRequirements
github.com/genkiyooka/GKApplication
github.com/genkiyooka/GKDynamicUI
github.com/genkiyooka/UAVCaptureImage
github.com/genkiyooka/GKSelfieTaker
github.com/genkiyooka/GKNetwerking