> You may be interested in having a look at QuollEyeTree which is a
> File Manager for Mac OS X v10.6 Snow Leopard or later.
>
> See a screen shot and download from
> http://binnie.id.au/QuollEyeTree.html

Can I assume from the URL that you wrote this?

I've never used a Mac, so I've no idea what the standard file manager can do. Can it do the equivalent of Ztree'z alt+K (display branch sizes)? If not, do you intend adding this to your program?

In my opinion, alt+K is one of the best features of Ztree, in terms of letting you understand your filesystem's space usage better than before.