[poss. from C. S. Lewis's "Narnia"
books] An awesomely arcane technique central to a program or
system, esp. one neither generally published nor available to
hackers at large (compare black art); one that could only have
been composed by a true wizard. Compiler optimization
techniques and many aspects of OS design used to be deep magic; m
graphics, and AI still are. Compare heavy wizardry. Esp.
found in comments of the form "Deep magic begins here...".
Compare voodoo programming.