Sabre and ATC core code are 50+ years old. Lockheed bought a particular unix source license 15 years ago for ATC sytems because the vendor would no longer suppo

Sabre and ATC core code are 50+ years old. Lockheed bought a particular unix source license 15 years ago for ATC sytems because the vendor would no longer support it. Everyone who wrote it is retired or dead.