- 1994 – 1996 68000 to PowerPC (with Fat binary)
- 2001 – 2003 OS 9 to Mac OS X (with Classic)
- 2006 – 2007 PowerPC to Intel (with Rosetta)
- 2018 – 2020 AppKit to UIKit (with Mazipan)
- xxxx – xxxx Intel to ARM
Apple has been living through quite a few of hardware and software transitions. From 68k to PowerPC processor; OS 9 to Mac OS X; and then PowerPC to Intel processor; and now Apple is bringing UIKit apps to macOS with Mazipan. It is heavily rumored that the future Macs would be powered by ARM processors too. It has come to a full circle from RISC to CISC and then back to RISC processors.
Change is the only constant. 😉