<jargon> A computer system or application program which continutes to be used because of the prohibitive cost of replacing or redesigning it and desprite its poor competitiveness and compatibility with modern equivalents. The implication is that the system is large, monolithic and difficult to modify.
If the legacy software only runs on antiquated hardware the cost of maintaining this may eventually outweigh the cost of replacing both the software and hardware unless some form of emulation or backward compatibility allows the software to run on new hardware.
(04 Aug 1996)