I've seen the same sort of folder hierarchy several times, always when choosing
Download Only from Software Update's
Update menu. I've been unsure how to proceed in such cases, and I haven't been able to find any information which even describes this situtation, let alone offers instructions.
Researching the issue, I found some interesting information at
Mac Dev Center: Software Delivery Guide: Managed Installs, particularly the sections on
Metapackages and
Distribution Packages.
Given the absence of any Apple-included instructions on how to install software which arrives in the format under discussion, I wonder if the top-level folder—in your case, iLife Support—is itself actually a metapackage which has somehow become unbundled?
I investigated one of my archived downloads, iTunes 7.6.2, whose folder structure is similar to yours; in addition to
iTunesX-7.6.2.dist, the Packages folder contains
iTunesX.pkg,
iTunesAccess.pkg, and
AppleMobileDeviceSupport.pkg. I'm guessing I simply double-clicked
iTunesX.pkg and iTunes 7.6.2 was installed without the other two packages being involved.
From the linked document, under Distribution Packages:
The central part of a distribution package is the distribution script. This is a JavaScript-based script file that contains all the information that defines an install experience...
...Distribution packages differ from metapackages in these areas:
...Installer ignores installation properties specified in the contained component packages (installation properties are specified by the distribution script). [my emphasis]
The emphasized text suggested an explanation as to why I was able successfully to install one of the component packages of the (unbundled) metapackage: each of the component packages contains its
own installation script. So I looked at
iTunesX.pkg's package contents, and sure enough, there was
iTunesX.dist!
Seeking corroboration for my theory that the top-level folder was meant to be a .mpkg bundle instead, I googled on
"iTunesAccess.pkg"; the first result was
a Betalogue post; one of the comments included a link to
this MacFixIt article.
