= C =
critical mass n.
In physics, the minimum amount of
fissionable material required to sustain a chain reaction. Of a
software product, describes a condition of the software such that
fixing one bug introduces one plus epsilon bugs. (This malady
has many causes: creeping featurism, ports to too many
disparate environments, poor initial design, etc.) When software
achieves critical mass, it can never be fixed; it can only be
discarded and rewritten.
--The Jargon File version 4.3.1, ed. ESR, autonoded by rescdsk.