why

do software packages come with multiple executable binaries? I tried reading my SICP but it doesn't seem to be in there.

Are some lines of execution so specific to one obscure condition that it's almost never used and they take it out of the main process image to make it smaller.?

>>6
It's best to make decisions as late as possible. If somebody upgrades their CPU while keeping the same installation, it'd be nice for software to just do the right thing instead of being bound to what the hardware was before. Same thing for taking a harddrive out and having it boot in a different machine.