[carmen]

up until OSX DP1 the x86 builds were regularly shipped to ADC members with a familiar Mac UI. it seemed like "Classic" aka OS7/8/9 binaries running with minimal emulation was the main reason x86 builds temporarily disappeared from the public eye (to a very strange shock & awe in journalistic circles upon its return)

[msbarnett]

Worth noting, though, that those x86 builds used, and that classic theme was built in, Display Postscript.

The newer Quartz display subsystem only ever shipped for the PowerPC in the dev previews.

[lukeh]

And the kernel changed from Mach 2.5 to Mach 3, see http://en.wikipedia.org/wiki/XNU.

[0x0]

There was also the odd Rhapsody project, which delivered a BSD-based Mac OS on x86 since 1997: http://en.wikipedia.org/wiki/Rhapsody_(operating_system) - wonder how that fits in with the quora post.