In GoboLinux, Fibo is a special user that assists Gobo, the superuser, during program installation. Fibo is responsible for the FiboSandbox, he is the only one who is given access to it.

Fibo is similar to the Unix nobody user, but the fundamental difference is while nobody never has write access to anything, Fibo is occasionally granted write permission to selected locations (specifically, during program installation, to the FiboSandbox and to the /Programs entry of the program being installed).

In a standard GoboLinux system, Fibo is userid 21 (which is, of course, a number of the Fibonacci sequence).