So 7zip and Winrar?
I joke, but only halfway. If you're only normal Windows user, you'd never hear of anything else (unless you want to go back to Winzip, which does still exist, but I've never heard of anyone using it any more).
But here’s one I heard literally two days ago: we counted three engineers (out of many) who knew that physical memory was not actually a giant flat space of contiguous addresses, and that there were multiple layers of address-mapping and region-joining glue logic between a program and the hardware, including in os libraries, and even inside the hardware.
Maybe knowing such information is archaic or useless for most engineers. But the good ones (or at least a certain flavor of the good ones) ask questions that lead them there.
That's the abstraction I'm working with when coding. Which is necessary because in most cases this should be an implementation detail.
It's all a layer below even OS programming. It's configured at the BIOS level and then performed in hardware. But that's the point, isn't it? Virtual memory is below the application programmer, too, but here we're chastising him for not understanding it. If we do that, shouldn't we equally chastise people for not understanding physical memory? Or speculative execution? Or head seeking and servo tracks? Or Ethernet line coding?
I also could no longer tell you how to balance a binary tree or implement Quicksort.
Worse, people who find it within themselves to ask questions anyway frequently face silence or a smackdown. The Internet's Own Boy remains no longer with us.
And I’ve hosted my own web server these last 20 years.