

As a base: The Linux kernel source, GNU software sources and compiler binaries so I can - in theory - write missing software myself. For convenience probably some stable, offline-installable, ready to use distros.
I would probably also archive sources and binaries of day-to-day software like web-browsers (I might still have an intranet to use), office tools, photo management software, audio/video players and all the codecs, etc.
I think that’s a solid starting point but im sure I’m missing something important :D
Good point! And Docker. Also: Encryption software