Mung is computer jargon for "to make repeate changes which individually may be reversible, yet which ultimately result in an unintentional, irreversible destruction of large portions of the original item." It was coined in 1958 at the Tech Model Railroad Club, at the Massachusetts Institute of Technology. In 1960, the backronym "Mash Until No Good" was created to describe Mung, and a while after that it was revised to "Mung Until No Good"—making it one of the first recursive acronyms, and lived on as a recursive command in the editing language TECO.