Greenspun's Rule basically covers that. Any sufficiently complicated C or Fortran program contains an ad hoc, informally-specified, bug-ridden, slow implementation of half of Common Lisp.
Although nowadays the art of programming is maturing enough that the inner platform sometimes is deliberately designed and well specified.
Maybe we need to rewrite that old law:
All programs expand until they contain a virtual machine. Those that cannot do so are replaced by ones that can.