Quote - >> ...true to a point, but that's not always the case. For instance: I double-dog-dare you to run a typical Windows 3.1 app in Vista. ;)

But we're not talking about operating systems, Tom.

Software is software is software. Windows, DAZ Studio, Linux, Poser... they all share many things in common: They're written in C and/or C++, they all had to be compiled, and they all sit on a hard disk as bits and bytes.

An app on an OS is conceptually no different than a file on an app, and backwards compatibility is a bugaboo that plagues them all.

Going even further, changes in an OS sometimes changes the app, which in turn changes the app's behavior with regards to the files it generates and loads.

Quote - We're talking about changes within a specific program's development. Illustrator 88 may have been built when System 6 was being used on the Mac, but I can still open those Illustrator 3 files within Illustrator CS under OSX 5.

This is because Apple went out of their way to insure as much backwards compatibility as possible under their circumstances (hence "Classic", Carbon Libraries, etc), and Adobe went out of their way to do the same with their apps. Not everyone has that luxury.

...and, OSX (or any operating system) is merely a collection of files, and in UNIX (which OSX is) everything (be it an app or a device) is literally just a file as far as the environment is concerned.

Quote - And I note our friend here still hasnt said what it is about the older content that restrains her so. I"m starting to think her issues lay elsewhere, but she hasnt quite figured that out yet.

"Her" name is Paul, a.k.a. The Prince of Lies.  Clealy*, Sir, you don't know him so well. :)

/P

(*typo intentional - he'll know why).