Historical note: this term derives from `bootstrap loader', a short
program that was read in from cards or paper tape, or toggled in
from the front panel switches. This program was always very short
(great efforts were expended on making it short in order to
minimize the labor and chance of error involved in toggling it in),
but was just smart enough to read in a slightly more complex
program (usually from a card or paper tape reader), to which it
handed control; this program in turn was smart enough to read the
application or operating system from a magnetic tape drive or disk
drive. Thus, in successive steps, the computer `pulled itself up
by its bootstraps' to a useful operating state. Nowadays the
bootstrap is usually found in ROM or EPROM, and reads the first
stage in from a fixed location on the disk, called the `boot
block'. When this program gains control, it is powerful enough to
load the actual OS and hand control over to it.

:bottom feeder: /n./ Syn. for {slopsucker}, derived from the
fishermen's and naturalists' term for finny creatures who subsist
on the primordial ooze.

:bottom-up implementation: /n./ Hackish opposite of the
techspeak term `top-down design'. It is now received wisdom in
most programming cultures that it is best to design from higher
levels of abstraction down to lower, specifying sequences of action
in increasing detail until you get to actual code. Hackers often
find (especially in exploratory designs that cannot be closely
specified in advance) that it works best to *build* things in
the opposite order, by writing and testing a clean set of primitive
operations and then knitting them together.