- Bell labs Unix, in its early days, were able to run on hardware considered “underpowered” even by the standard of that day — P33 [[art of unix programming]]. I believe contemporary kernels were unable to run on those low-end machines.
- Linux (P77) has a similar characteristic. In the 1990’s the big commercial Unixes targeted enterprise-class hardware but Linux emphasized doing more with less. Today, Linux powers 99% of the world’s most powerful supercomputers but Linux also runs on low-end or obsolete hardware.
In both cases, I feel that an OS designed with very low minimum hardware requirement turned out to be actually more efficient, more adaptable, more versatile, more powerful than their conventional competitors.