Hacker News Reader

Not every. The ones that are distributed with the OS X base install usually are dynamically linked against.

My current project I'm working on links against the standard Cocoa frameworks, zlib, Core Audio, Audio Unit framework and the Accelerate framework. Yet the Frameworks directory in the app bundle is empty.

Well, if I'm not mistaken, Windows linking usually involves re-calculating offsets in the library code, so several versions of libraries are kept in Windows too. The only thing that is theoretically saved is disk space.

How often do you really have multiple third-party apps using multiple copies of the same third-party framework? How many third-party frameworks maintain binary compatibility between versions so that apps linked against different versions could still share a single installation of it?