Hackers
Used in the book Eric to describe Eric, a callow youth, pallid with having spent too much time indoors, who has inherited his late uncle's books of demonology and necromancy and who is keen to explore what may be done with them. While his main motivation is having his three wishes granted, Eric is also genuinely keen to explore the limits of applied necromancy. At times - as when stranded with Rincewind at the creation of the world - his dialogue is of the well, yes. I can hijack the source codex and re-route it through the end-user ritual variety, and is not dissimilar to that used by computer hackers on Roundworld.
However, the gentlemen of The Smoking Gnu in Going Postal, who are just as intent with surreptitiously finding out the limits of what the clacks system can do, prefer to be described as Crackers....