Vernor Vinge's A Deepness in the Sky depicts a human society thousands of years in the future, in which pretty much all software has already been written; it's just a matter of finding it. So programmer-archaeologists search archives and run code on emulators in emulators in emulators as far back as needed. <https://garethrees.org/2013/06/12/archaeology/>
(Heck, recently I migrated a VM to its third hypervisor. It began as a physical machine a quarter century ago.)