Greenspun's tenth rule (actually the only rule) states that:
Any sufficiently complicated C or Fortran program contains an ad hoc, informally-specified, bug-ridden, slow implementation of half of Common Lisp.
My memory is that there are some papers on the topic, perhaps for Borland's Quattro (spreadsheet) project and possibly others. Google is unhelpful, maybe the right search terms are not coming to mind. I am looking for papers or articles supporting this claim, if any.