The origin of the magic numbers of 0xCAFEBABE and 0xFEEDFACE in relation to mach-o file formats and Java’s .class file magic number were recently discussed. There are speculations that Java’s magic number was chosen by Mike DeMoney, an ex-NeXT employee, but he clarified that the numbers were actually selected by someone else. Another theory suggests that the magic number was inspired by a barista named ‘Cafe babe’ at Pete’s Coffee in Palo Alto. However, the true story behind Java’s choice of magic number involves James Gosling’s experience at a place called St Michael’s Alley. The history of these magic numbers is an intriguing and humorous tale.
http://radio-weblogs.com/0100490/2003/01/28.html