A monkey patch is a way to modify the behaviour of Zope or a Product without altering the original code. Useful for fixes that have to live alongside the original code for a while, like security hotfixes, behavioural changes, etc. The term "monkey patch" seems to have originated as follows: First it was "guerilla patch", referring to code that sneakily changes other code at runtime without any rules. In Zope 2, sometimes these patches engage in battle with each other. This term went around Zope Corporation for a while. People heard it as "gorilla patch", though, since the two words sound very much alike, and the word gorilla is heard more often. So, when someone created a guerilla patch very carefully and tried to avoid any battles, they tried to make it sound less forceful by calling it a monkey patch. The term stuck.