= S =
software rot n.
Term used to describe the tendency of
software that has not been used in a while to lose; such
failure may be semi-humorously ascribed to bit rot. More
commonly, `software rot' strikes when a program's assumptions
become out of date. If the design was insufficiently robust,
this may cause it to fail in mysterious ways. Syn. `code rot'.
See also link rot.
For example, owing to endemic shortsightedness in the design of
COBOL programs, a good number of them succumbed to software rot
when their 2-digit year counters underwent wrap around at the
beginning of the year 2000. Actually, related lossages often
afflict centenarians who have to deal with computer software
designed by unimaginative clods. One such incident became the
focus of a minor public flap in 1990, when a gentleman born in 1889
applied for a driver's license renewal in Raleigh, North Carolina.
The new system refused to issue the card, probably because with
2-digit years the ages 101 and 1 cannot be distinguished.
Historical note: Software rot in an even funnier sense than the
mythical one was a real problem on early research computers (e.g.,
the R1; see grind crank). If a program that depended on a
peculiar instruction hadn't been run in quite a while, the user
might discover that the opcodes no longer did the same things they
once did. ("Hey, so-and-so needs an instruction to do
such-and-such. We can snarf this opcode, right? No one uses
Another classic example of this sprang from the time an MIT hacker
found a simple way to double the speed of the unconditional jump
instruction on a PDP-6, so he patched the hardware. Unfortunately,
this broke some fragile timing software in a music-playing program,
throwing its output out of tune. This was fixed by adding a
defensive initialization routine to compare the speed of a timing
loop with the real-time clock; in other words, it figured out how
fast the PDP-6 was that day, and corrected appropriately.
Compare bit rot.
--The Jargon File version 4.3.1, ed. ESR, autonoded by rescdsk.