Related Clues:
- Programmer's language
- Bell Labs op-sys name
- Grid
- Alternative to Windows
- System for servers
- Popular computer operating system
- Popular operating system
- Lattice
- Server system
- Ken Thompson helped develop it
- System developed at Bell Laboratories
- Maze
- Operating system developed at Bell Labs
- Operating system that doesn't do Windows?
- Operating system designed by AT&T employees