> Will MorphOS also be Spectre and Meltdown compatible? ;-)

It's already Spectre-compatible on PowerPC / Power Architecture ;-)

http://tenfourfox.blogspot.com/2018/01/is-powerpc-susceptible-to-spectre-yep.html
http://tenfourfox.blogspot.com/2018/01/more-about-spectre-and-powerpc-or-why.html

In short, any OS on any CPU that does speculative execution is Spectre-vulnerable unless appropriate software measures are taken in the OS. And also with PowerPC the general rule applies that the older the CPU the more resilient it is against the vulnerability (except for future CPUs that will have counter-measures implemented).

However, I suspect that MorphOS can't be patched against Spectre because of its singular address space nature. A comment by a MorphOS team member on this would be appreciated.