Mostly it is an "end-volution" of the Apple II.
The CPU was the 16 bits version of the 6502
In addition, it has a really nice sound chip and nice graphics.
It could play all the Apple // softwares.
And the OS is "mac-ish"
My understanding is that the Apple IIG was designed by members of the Mac team. It's also worth noting that the IIGS had resolution, speed, memory and color that would not be matched on the Mac or PC for years more to come. It was an extraordinary machine. (disclosure: I created HyperStudio for the Apple IIGS in 1988, and the rest, as they say, is history).
Wow! I _loved_ HyperStudio. We learned so much using it in my school, and I still actually have a floppy disc in my collection with my HyperStudio stack. It's an honour to be able to tip my hat and raise a glass for your contribution. :)
