*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 nonstop 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 takeoff. 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 and 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?"