This makes sense if you're releasing versioned software builds to 3rd parties. If you're running it internally (e.g. as a SaaS company) then there's much less cause to run an old versions, let alone one from 20 years ago.
Yeah. I get that. Getting enterprise people to migrate or go off-prem for everything takes some time. And some like custom versons! I just like to snap-shot everything (including the tool chain) so that I can recreate the past out of my repository at any time for any reason. (I'm weird like that - I expect the same out of legal, ops and accounting as well)
Maybe I'm old - but I don't trust Quickbooks-in-the-Cloud.
EDIT: But I use 'em!
I like this idea. Did you also archive the operating system the build was running on ?
If not, this should be trivial to replicate today using docker containers.
We did! This was before docker. we stuck it on mag-tape and DVD, DVD stayed on-site, and the mag-tape went to Iron Mountain. We had escrow agreements with our customers (Chase, Citi, Amex, HSBC, Deutche, etc.) that if we went tits up, they would get a copy of the code with the docs.
The thing that made it work, though, was the fire-drills. Once a quarter (at the beginning, later it was once a year), we would go buy about 10 servers from dell and set them up in the common-room and say to the employees. "We just got hit by a meteor last night. Get us up from off-sites, including all company documentation. Re-inflate the company in 4 hours. Start Now". Of course we all failed (sometimes the backups didn't even work!), but we got to the point where we could re-inflate the company in four hours. I was so proud of those people.
EDIT: To be clear - maybe I am REALLY old-school, but every time we did a release, we archived our tool-chain (GCC blah blah, Make blah blah, bash blah blah), our depencies, our vendor libraries and our code, so that IF in 20 years, if we had to rebuild a particular release (12.x) for a particular client (Chase) on a particular platform (AIX), we could do so de novo. Maybe that was overkill, but in a world where everything changes, why wouldn't you snapshot everything for every release?