The Jargon File (version 4.4.7, 29 Dec 2003):
programming fluid n. 1. Coffee. 2. Cola. 3. Any caffeinacious stimulant. Many hackers consider these essential for those all-night hacking runs. See wirewater.The Free On-line Dictionary of Computing (30 December 2018):
programming fluid(Or "wirewater") Coffee, unleaded coffee (decaffeinated), Cola, or any caffeinacious stimulant. Many hackers consider these essential for those all-night hacking runs. (1996-05-01)