crawling horror
Ancient crufty hardware or software that is kept obstinately alive by forces beyond the control of the hackers at a site. Like dusty deck or gonkulator, but connotes that the thing described is not just an irritation but an active menace to health and sanity. "Mostly we code new stuff in C, but they pay us to maintain one big Fortran II application from nineteen-sixty-X that's a real crawling horror."
Compare WOMBAT.