A legacy system is any information system that _resists change_. See * M. L. Brodie and M. Stonebraker. _Migrating Legacy Systems: Gateways, Interfaces and the Incremental Approach._ Morgan Kaufman Publishers, 1995. Legacy system characteristics: large, geriatric, outdated database technology, outdated languages, inflexible, brittle. ---- CategorySoftwareEvolution | Contributions by ArieVanDeursen