ICANN
ICANN is quite a bizarre outfit. It has–by the standards of most people—huge sums of cash to play with, handed over pretty much for no reason at all.
You see, ICANN (mostly) has authority over the root zone. This is the place that DNS servers all over the world look at first when they don’t know the answer to a query themselves: they start at the root zone, and work down (so, if you’re looking up www.google.com, your friendly neighbourhood DNS server will ask the root servers for the IP addresses of the servers which deal with ‘.com’, then ask those for the addresses of the servers which deal with ‘google.com’, and so on, until it gets some kind of definitive answer).
The thing about all of this is that it’s all built on… nothing.
The only reason that the root zone that ICANN publishes is important is because it’s carried by the root servers (operated by various organisations across the world, including ICANN itself). Fair enough so far.
Except the only reason we care about the root servers is because every recursive nameserver out there (i.e., the ones your computer talks to in order to look up addresses) ships with a set of “hints” which tell it which servers to talk to.
If, hypothetically, you were to change those hints file and point it at a different set of servers which carried a different root zone, ICANN would become irrelevant for everybody using the servers with a modified configuration.
In fact, there have been efforts over the years to set up alternate root servers and do precisely this by people who aren’t entirely satisfied with the way that ICANN’s run.
The funny thing is, most companies (including ISPs) tend to use whatever hints were supplied with the DNS server they use (typically ISC BIND or Microsoft DNS Server), which usually means it’s the set of hints that ship with the operating system—be it Windows, Linux, BSD, Solaris, or whatever.
ICANN—a company with budgets of millions of pounds a year—has a purpose solely because operating system vendors (free and commercial alike) allow it to.
This is how the Internet works.
