Air travel became a primary means of transportation in the early 21st Century. It appears that there were many warring factions (as evidenced by "price wars") and based on this document, recently discovered, it's not apparent as to the reason why they would have to compete for business? The agencies involved obviously provided substandard services, yet homo sapiens relied heavily on them and favored one agency over the other with the greatest loyalty. They didn't even seem to attempt to experience other flight agencies after they got comfortable with one. Their loyalty, extended to their crude computational machines which they "programmed*" to operate using the agencies' "language.*" Visual documentation of these questionable flight agencies has not been found, but it is a known fact that Linux Airline passengers were forced to wear Red Fedoras to cover their cranium (Pa'Tukra declares it was a tribal ritual).
Please enjoy this enlightening bit of history and be thankful you depend on USUnitedDeltaNorthSouthWestEastern Air Transport and Warp!

UNIX Airways
Everyone brings one piece of the plane along when they come
to the airport.  They all go out on the runway and put the
plane together piece by piece, arguing non-stop about what
kind of plane they are supposed to be building.

Air DOS

Everybody pushes the airplane until it glides, then they jump
on and let the plane coast until it hits the ground again.
Then they push again, jump on again, and so on ...

MAC Airlines

All the stewards, captains, baggage handlers, and ticket agents
look and act exactly the same.  Every time you ask questions
about details, you are gently but firmly told that you don't
need to know, don't want to know, and everything will be done
for you without your ever having to know, so just shut up.

Windows Air

The terminal is pretty and colorful, with friendly stewards,
easy baggage check and boarding, and a smooth take-off.  After
about 10 minutes in the air, the plane explodes with no warning
whatsoever.

Windows NT Air

Just like Windows Air, but costs more, uses much bigger planes,
and takes out all the other aircraft within a 40-mile radius
when it explodes.

Linux Air

Disgruntled employees of all the other OS airlines decide to
start their own airline.  They build the planes, ticket counters,
and pave the runways themselves.  They charge a small fee to
cover the cost of printing the ticket, but you can also download
and print the ticket yourself.  When you board the plane, you
are given a seat, four bolts, a wrench and a copy of the
seat-HOWTO.html.  Once settled, the fully adjustable seat is
very comfortable, the plane leaves and arrives on time without
a single problem, the in-flight meal is wonderful.  You try to
tell customers of the other airlines about the great trip, but
all they can say is, "You had to do what with the seat?"

~*~*~*Author Unknown*~*~*~

*Additional information on "programming" and "language" are available in the Burgonian Species Library.