If Operating Systems were airlines...

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.  They constantly upgrade the design while they continue to work on it, but it never really gets fully completed.  Amazingly enough, the airplane seldom crashes, and UNIX airways has a major share of the airfreight business.

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.  You never quite trust that it's safe or that you'll make it to the proper destination. Recently, Mac Airlines has been painting their airplanes different colors.

Windows Air

The terminal is pretty and colourful, with friendly stewards, easy baggage check and boarding, and a smooth take-off.  On board, there are all sorts of extra amenities like air-phones, games, movies, laundry facilities, etc. However, the planes frequently explode in mid-air with no warning whatsoever.

Windows NT Air

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

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 "seat-HOWTO". 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?"

VMS Air

You get to the airport and there are no amenities.  But everything you need is there.  The guards at the security check points are awake and alert and thorough but quick.  On board, things are pretty plain but again everything works and the airplane is fast.
The airline has recently come out with a new fleet of airplanes with twice as many engines as the old ones.  Plus, the airplanes have all sorts of hooks for connecting together airplanes.  Finally, some of these airplanes have been sold to UNIX air and Linux air.

RSX-11 Air

Some people have been flying RSX-11 air for decades and they are quite happy with it, even though the company is still flying DC-3s.