Benevolent Dictator For Life

(sometimes Self-Appointed) Benevolent Dictator For Life is the title given to many Open Source pioneers, usually to officially(ish) recognize their authority as the "end-all" of discussions related to that project.

Probably the one who wields his SupremePowers? (and title) with the most frequency is GuidoVanRossum, the BDFL of the PythonLanguage.