MEDUSA, (since 2004 MEDUSA4) is a CAD program used in the areas of mechanical and plant engineering by manufacturers and Engineering, Procurement and Construction (EPC) companies. The system's history is closely tied to the beginnings of mainstream CAD and the research culture fostered by Cambridge University and the UK government as well as the resulting transformation of Cambridge into a world-class tech centre in the 1980s.

In Greek mythology Medusa (, ; Μέδουσα "guardian, protectress") was a monster, a Gorgon, generally described as a winged human female with a hideous face and living venomous snakes in place of hair. Gazers on her face would turn to stone. Most sources describe her as the daughter of Phorcys and Ceto, though the author Hyginus (Fabulae Preface) makes Medusa the daughter of Gorgon and Ceto. According to Hesiod and Aeschylus, she lived and died on an island named Sarpedon, somewhere near Cisthene. The 2nd-century BCE novelist Dionysios Skytobrachion puts her somewhere in Libya, where Herodotus had said the Berbers originated her myth, as part of their religion.