Plan 9 is an incomplete name. That company refers to themselves as
PLAN9, which is not trademarked. "Plan 9 from Bell Labs" is the full
name of the OS, and it is copyrighted. I don't know if "Plan 9 from
Outer Space" is copyrighted.

On Feb 2, 2008, at 8:37 PM, mattmobile@proweb.co.uk wrote:

> Is "Plan 9" trademarked?
> IANAL but there could be a problem
>
> http://www.plan9software.com/