= I =
1. [numerical analysis] Said of an
algorithm or computational method that tends to blow up because of
accumulated roundoff error or poor convergence properties.
2. Software that bypasses the defined OS interfaces to do
things (like screen, keyboard, and disk I/O) itself, often in a way
that depends on the hardware of the machine it is running on or
which is nonportable or incompatible with other pieces of software.
In the IBM PC/MS-DOS world, there is a folk theorem (nearly true)
to the effect that (owing to gross inadequacies and performance
penalties in the OS interface) all interesting applications are
ill-behaved. See also bare metal. Oppose well-behaved,
compare PC-ism. See mess-dos.
--The Jargon File version 4.3.1, ed. ESR, autonoded by rescdsk.