Code or designs thAT trade on a particularly intimATe knowledge or experience of a particular operATing system or language or complex applicATion interface. Distinguished from deep magic, which trades more on arcane *theoretical* knowledge. Writing device drivers is heavy wizardry so is interfacing to X (sense 2) without a toolkit. Especially found in source-code comments of the form "Heavy wizardry begins here". Compare voodoo programming. [Jargon File]