A piece of code or a coding technique that depends on the protected multi-tasking environment with relatively low process-spawn overhead that exists on virtual-memory Unix systems. Common unixisms include: gratuitous use of fork(2); the assumption that certain undocumented but well-known features of Unix libraries such as stdio(3) are supported elsewhere; reliance on obscure side-effects of system calls (use of sleep(2) with a 0 argument to clue the scheduler that you're willing to give up your time-slice, for example); the assumption that freshly allocated memory is zeroed; and the assumption that fragmentation problems won't arise from never free()ing memory. Compare vaxocentrism; see also New Jersey.