The .io domain has considerable usage
unrelated to the British Indian Ocean Territory.

In computer science, "IO" or "I/O" is commonly used
as an abbreviation for input/output,
which makes the .io domain desirable for services
that want to be associated with technology.

.io domains are often used for
    open source projects,
    application programming interfaces ("APIs"),
    startup companies,
    video games,
    and other online services.