Greenspun's Tenth

A compilation of instances of Greenspun’s Tenth Rule at work spotted in the wild
275 words2 min

One of my favorite pieces of software lore is Greenspun’s Tenth Rule:

Greenspun’s Tenth Rule (GTR)
Any sufficiently complicated C or Fortran program contains an ad hoc, informally–specified, bug–ridden, slow implementation of half of Common Lisp.

This page collects occurences of the strict formulation of GTR, as well as the following generalizations:

Generalized Greenspun’s Tenth Rule (GGTR)
Any sufficiently complicated program contains an ad hoc, informally–specified, bug–ridden, slow implementation of half of Common Lisp.
Generalized GGTR (G3TR)
Any sufficiently complicated program contains an ad hoc, informally–specified, bug–ridden, slow implementation of half of a high–level scripting language.

GTR

Any sufficiently complicated C or Fortran program contains an ad hoc, informally–specified, bug–ridden, slow implementation of half of Common Lisp.

GGTR

Any sufficiently complicated program contains an ad hoc, informally–specified, bug–ridden, slow implementation of half of Common Lisp.

G3TR

Any sufficiently complicated program contains an ad hoc, informally–specified, bug–ridden, slow implementation of half of a high–level scripting language.