MS-DOS Airline
Everybody pushes the airplane until it glides, then they jump on and let the plane coast until it crashes again, then they push again jump on again, and so on. 
Mac Airline
All the stewards, stewardesses, captains, baggage handlers, and ticket agents look the same, act the same, and talk the same. Every time you ask questions about details, you are told you don't need to know, don't want to know, and would you please return to your seat and marvel at the image quality of the in-flight movie. 
OS/2 Airline
To board the plane, you have your ticket stamped ten different times by standing in ten different lines. Then you fill our a form showing where you want to sit and whether the plane should look and feel like an ocean liner, a passenger train or a bus. If you succeed in getting on the plane and the plane succeeds in taking off the ground, you have a wonderful trip...except for the time when the rudder and flaps get frozen in position, in which case you will just have time to say your prayers and get in crash position. 
Windows 95 Airline
The airport terminal is nice and colorful, with friendly stewards and stewardesses, and easy access to the plane. After the plane arrives, 6 months late, you have a completely uneventful takeoff... then, once in the air the plane blows up without any warning whatsoever. 
Windows NT Airline
All the passengers carry their seats out onto the tarmac, placing the chairs in the outline of a plane. They all sit down, flap their arms and make jet swooshing sounds as if they are really flying. 
Windows XPAirline
The airplane is very pretty, and each passenger gets to choose their own colour and pattern for the paintwork, and their own favourite engine noise. Unfortunately the plane is so heavy and so slow that it is unable to get airbourne,and crashes at the end of the runway. When parked in the hanger, unresolved security bugs in the planes doors AND windows AND luggage-bay AND engines AND wings AND body panels allow theives to break in and steal all the seats.
Unix Airline
Each passenger brings a piece of the airplane and a box of tools to the airport. They gather on the tarmac, arguing constantly about what kind of plane they want to build and how to put it together. Eventually, they build several different aircraft, but give them all the same name. Some passengers actually reach their destinations. All passengers believe they got there. 
BEOS Airline
There is no airplane. The passengers gather and shout for an airplane, then wait and wait and wait and wait. A bunch of people come, each carrying one piece of the plane with them. These people all go out on the runway and put the plane together piece by piece, arguing constantly about what kind of plane they're building. The plane finally takes off, leaving the passengers on the ground waiting and waiting and waiting and waiting. After the plane lands, the pilot telephones the passengers at the departing airport to inform them that they have arrived. 
Newton Airline
After buying your ticket 18 months in advance, you finally get to board the plane. Upon boarding the plane you are asked your name. After 46 times, the crew member recognizes your name and then you are allowed to take your seat. As you are getting ready to take your seat, the steward announces that you have to repeat the boarding process because they are out of room and need to recount to make sure they can take more passengers. 
VMS Airline
The passengers all gather in the hanger, watching hundreds of technicians check the flight systems on this immense, luxury aircraft. This plane has at least 10 engines and seats over 1,000 passengers. All the passengers scramble aboard, as do the necessary complement of 200 technicians. The pilot takes his place up in the glass cockpit. He guns the engines, only to realise that the plane is too big to get through the hangar doors. 
Linux Airline
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 for free. 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?"