So this gets complicated so
Improv 1.0 is available on m68k next hw.
Improv 2.0 was only available for windows x86.
Lighthouse design quantrix for nextstep is available on m68k, x86, hp-parisc and sun hardware.
Then there’s an offshoot of lighthouse design quantrix which is quantrix modeller written in Java and available for windows and Mac. It costs $2500/year.
I’m learning improv on m68k and quantrix(the manuals interchange freely) on m68k/x86.