Check out this video of Steve Jobs demoing NeXTSTEP Release 3. The video shows many features that are now present in Mac OS X. NeXTSTEP 3 was released at the end of 1992.
When I watched this video I could not stopped myself the feature of the current Mac OS X. It is exist now what they were thinking and doing in 1992. So what are they thinking now for next 20 years :) amazing things must be there.....!
I used to write code for NeXTStep back in college in the early 90's. At the time, we were using NeXT PCs (yes there was such a thing) and I also had an x86 edition running at home. The OS was graphics intensive and development was mostly in Objective-C (like iPhone), so it really needed faster hardware. At the time, I was salivating for the Intel 486 to run NeXTStep cause it was way too slow on the 386!