If it had been written in some other scripting language then I'd guess you would have had even more issues upgrading! Because Perl, despite all its supposed warts & bad image, remains highly backward compatible.
NB. The biggest issues I've seen in upgrading are modules that use C libraries (unfortunately things do change over time!).
As an example I'm still running a Perl web system & data munging backend that I wrote back in 2001 with only minor tweaks over the years for new/modern systems.
Exactly. Perl 5 exists since 1994, so it's probably Perl 5 code there which needs probably little to no changes to run even today on the latest 5.x interpreter. I don't understand what were the issues that 72deluxe faced.
I think it was renamed modules between versions? I never got to the bottom of it. In fact, I aborted migrating it and ended up leaving it running, but instead virtualised the machine (that was fun!)
If I had known what I was doing with Perl, it might have been better. I was a bit harsh on Perl, apologies. But it still stands that migration on Linux boxes isn't massively easy or fun (not that Windows is either)
NB. The biggest issues I've seen in upgrading are modules that use C libraries (unfortunately things do change over time!).
As an example I'm still running a Perl web system & data munging backend that I wrote back in 2001 with only minor tweaks over the years for new/modern systems.