What use cases are there for defining a new root class?

Question

We know that in Objective-C there are two main root classes: NSObject and NSProxy. There are other roots (mainly for private and legacy purposes)

Answer 1

Companies like the OmniGroup have defined a version of NSObject to use as their own base class for everything.

It's essentially a subclass of NSObject with some debug stuff. Other than that, it's usually a terrible idea to fight the framework.

Find Omni's code here: https://github.com/omnigroup/OmniGroup