When I search the real-time airline information by Google, I found a site named
It looks so strange. I have never seen a top level domain with four letters. There are very common three letter domain or two letter domain, like .com, .net, .uk, .cn, .cc.
This time it is four letters – aero.
After doing some research, I got the answer.
.aero – the world’s first industry-based top level Internet domain
Reserved exclusively for aviation, .aero is inspiring a revolution in the way people access and use air transport information.
Registration service is provided by

Not anyone can register an AERO domain. The eligible rule is here
It’s so cool to have a dot AERO domain.