Related Clues:
- Ken Thompson helped develop it
- System developed at Bell Laboratories
- Operating system developed at Bell Labs
- Operating system that doesn't do Windows?
- Operating system designed by AT&T employees
- Bell Labs invention
- Operating system since the '60s
- System developed at Bell Labs
- 2001 Microsoft debut
- Computer operating system since the '60s
- Operating system option
- Basis of the Solaris Operating System
- Computer system developed at AT&T
- OS choice
- Bell Labs operating system