DOS Pepsi:
Requires you to use your own bottle opener, and requires you to read the directions carefully before opening the bottle. Originally only came in an 8-oz. bottle, but now comes in a 16-oz. bottle. However, the bottle is divided into 8 compartments of 2 oz. each, which have to be accessed separately. Soon to be discontinued, although a lot of people are going to keep drinking it after it's no longer available.

Mac Pepsi:
At first, came only a 16-oz. bottle, but now comes in a 32-oz. bottle. Considered by many to be a "Diet" Pepsi. All the bottles look identical. When you take one from the fridge, it opens itself. The ingredients list is not on the bottle. If you call to ask about the ingredients, you are told that "you don't need to know." A notice on the side reminds you to drag your empties to the trashcan.

Windows 3.1 Pepsi:
The world's most popular. Comes in a 16-oz. bottle that looks a lot like Mac Pepsi. Requires that you already own a DOS Pepsi. Claims that it allows you to drink several DOS Pepsi's simultaneously, but in reality you can only drink a few of them, very slowly, especially slowly if you are drinking the Windows Pepsi at the same time. Sometimes, for apparently no reason, a bottle of Windows Pepsi will explode when you open it.

OS/2 Pepsi:
Comes in a 32-oz bottle. Does allow you to drink several DOS Pepsi's simultaneously. Allows you to drink Windows 3.1 Pepsi simultaneously too, but somewhat slower. Advertises that its bottles won't explode when you open them, even if you shake them up. You never really see anyone drinking OS/2 Pepsi, but the manufacturer (International Pepsi Manufacturing) claims that 9 million six-packs have been sold.

Windows 95 Pepsi:
You couldn't buy it till now, but a lot of people have taste-tested it and claim it's wonderful. The bottle looks a lot like Mac Pepsi's bottle, but tastes more like Windows 3.1 Pepsi. It comes in 32-oz. bottles, but when you look inside, the bottles only have 16 oz. of Pepsi in them. Most people will probably keep drinking Windows 3.1 Pepsi until their friends try Windows 95 Pepsi and say they like it. The ingredients list, when you look at the small print, has some of the same ingredients that come in DOS Pepsi, even though the manufacturer claims that this is an entirely new product.

Windows NT Pepsi:
Comes in 32-oz. bottles, but you can only buy it by the truckload. This causes most people to have to go out and buy bigger refrigerators. The bottle looks just like Windows 3.1 Pepsi's, but the company promises to change the bottle to look just like Windows 95 Pepsi's - after Windows 95 Pepsi starts shipping. Touted as an "industrial strength" Pepsi, and suggested only for use in established pizza parlors.

Unix Pepsi:
Comes in several different brands, in bottles ranging from 8 oz. to 64 oz. Drinkers of Unix Pepsi display fierce brand loyalty, even though they claim that all the different brands taste almost identical. Sometimes the pop-tops break off when you try to open them, so you have to have your own bottle opener around for those occasions, in which case you either need a complete set of instructions or a friend who has been drinking Unix Pepsi for several years.

AmigaDOS Pepsi:
The company has gone out of business, but their recipe has been picked up by some weird German company, so now this Pepsi will be an import. This Pepsi never really sold very well because the original manufacturer didn't understand marketing. Like Unix Pepsi, AmigaDOS Pepsi fans are an extremely loyal and loud group. It originally came in a 16-oz. bottle, but now comes in 32-oz. bottles too. When this bottle was originally introduced, it appeared flashy and colorful, but the design hasn't changed much over the years, so it appears dated now. Critics of this Pepsi claim that it is only meant for watching TV anyway.

VMS Pepsi:
Requires minimal user interaction, except for popping the top and sipping. However bottles have been known on occasion to explode, or contain extremely un-Pepsi-like contents. Best drunk in high pressure development environments. When you call the manufacturer for the list of ingredients, you're told that is proprietary and referred to an unknown listing in the manuals published by the FDA. Rumors are that this was once listed in the Physicians' Desk Reference as a tranquilizer, but no one can claim to have actually seen it.