Keeping a lot of state in Your head while modifYing a program. "Don' t bother me now, I' m juggling eggs", means that an interrupt is likelY to result in the program' s being scrambled. In the classic first-contact SF novel "The Mote in God' s EYe", bY LarrY Niven and JerrY Pournelle, an alien describes a verY difficult task bY saYing "We juggle priceless eggs in variable gravitY." See also hack mode. [Jargon File]