On 22 Mar 2018, at 21:05, Bakul Shah <bakul(a)bitblocks.com> wrote:
I was thinking about a similar issue after reading Bradshaw's
message about FORTRAN programs being critical to his country's
security. What happens in 50-100 years when such programs have
been in use for a long time but none of the original authors
may be alive? The world may have moved on to newer languages
and there may be very few people who study "ancient" computer
languages and even they won't have in-depth experience to
understand the nuances & traps of these languages well enough.
No guarantee that FORTRAN will be in much use then! Will it be
like in science fiction where ancient spaceships continue
working but no one knows what to do when they break?
My experience of large systems like this is that this isn't how they work at all.
The program I deal with (which is around 5 million lines naively (counting a lot of stuff
which probably is not source but is in the source tree)) is looked after by probably
several hundred people. It's been through several major changes in its essential
guts and in the next ten years or so it will be entirely replaced by a new version of
itself to deal with scaling problems inherent in the current implementation. We get a new
machine every few years onto which it needs to be ported, and those machines have not all
been just faster versions of the previous one, and will probably never be so.
What it doesn't do is to just sit there as some sacred artifact which no-one
understands, and it's unlikely ever to do so. The requirements for it to become like
that would be at least that the technology of large-scale computers was entirely stable,
compilers, libraries and operating systems had become entirely stable and people had
stopped caring about making it do what it does better. None of those things seems very
likely to me.
(Just to be clear: this thing isn't simulating bombs: it's forecasting the
weather.)
--tim