Clue: Longtime computer operating system

Answer: UNIX

Length: 4

---

Similar Clues:

• Widely used computer operating system (UNIX with 4 letters)
• Core of a computer's operating system (KERNEL with 6 letters)
• Computer operating system (e.g. LINUX with 5 letters)
• Old computer operating system (DOS with 3 letters)
• Computer operating system since the '60s (UNIX with 4 letters)
• Computer operating system developed by Bell Labs (UNIX with 4 letters)
• Computer operating system developed at Bell Labs (UNIX with 4 letters)
• Computer operating system with a penguin mascot (LINUX with 5 letters)
• Like computer operating systems that allow many people to work simultaneously (MLTSR with 5 letters)
• Multiuser computer operating system (UNIX with 4 letters)