The Fathers of eXtreme Programming
WardCunningham - the inventor
KentBeck - the articulator
RonJeffries - the realizer
Wow. Three is a wonderful number. So many possibilities. Three Musketeers, Three Stooges. Siggy Freud and Eric Berne's tripartite views of personality. Father, Son and Holy Ghost. The list goes on and on. (and on.) (Sorry, but the very RuleOfThree you're citing compelled me to add that.)
I'm honored to be listed in the same breath with these giants of the field. And grateful for not being named "the ranter". -- RonJeffries
Presumably, the term "The Three Extremos" is a reference to a 1986 comedic film named "The Three Amigos," starring Steve Martin, Martin Short, and Chevy Chase. See http://us.imdb.com/Title?0092086 for more information.
Indirectly. The ThreeAmigos was a reference and TheThreeExtremos is a reference to that.