What it was: IBM's successor to DOS, released in 1987 and originally a coproduction with Microsoft.
Underdog to: Microsoft Windows, which was once an underdog itself, then became a massive success starting with version 3.0...whereupon Microsoft kind of lost interest in OS.2.
Notable virtues: Robust underpinnings in an era when DOS and Windows were especially messy; sported features such as long file names and TCP/IP long before Windows got them; could run Windows 3.x apps.
Why it was an underdog: This article does a good job of explaining why OS/2 never caught on. It demanded more horsepower than most computers could muster in the 1980s; it never got all the drivers and applications it needed; and IBM (Charlie Chaplin ads aside) wasn't very good at consumer marketing. Eventually, Microsoft did everything in its power to prevent PC manufacturers from preinstalling OS/2 -- including charging computer makers a fee for every system that came off their assembly lines, whether or not Windows were on them.
Random factoid: OS/2 had some truly lousy ads, such as this one -- which unconvincingly describes it as "totally cool."
What it was: A line of personal computers originally sold by Commodore in the 1980s and early 1990s. (Yes, I know Amiga lives on, implausibly, as an operating system -- but it's no longer an underdog. Today's Amiga is an oddity.)
Underdog to: PCs -- and, to some degree, Macs. Maybe even the lowly Atari ST. Basically, any computing platform that sold better than the Amiga did, or seemed like it might do so.
Notable virtues: Exceptional multimedia and mulitasking, starting in an era when most computers didn't do multimedia and multitasking; a pioneering desktop video machine.
What made it an underdog: Nine letters: C-O-M-M-O-D-O-R-E. The company may have sold more computers than anyone else in the 1980s, but it didn't really know what it had in the Amiga. If you were a fan of the platform -- and I was -- you generally harbored a nagging suspicion that Commodore was trying to murder it through lousy advertising and boneheaded strategic moves. (The company itself died in 1994.)
Random factoid: In 1993, the Amiga spawned the Amiga CD32, which Commodore claimed was the first CD-based gaming console.
What it is: An open-source operating system initiated by Finnish student Linus Torvalds in 1991.
Unde rdog to: A closed-source operating system called Windows.
Notable virtues: Solid; modest hardware requirements; safe from Windows security issues; infinitely customizable; can be tailored to run anything from a server to a cell phone; the original shining example of how an open-source community can change the world.
What makes it an underdog: I mentioned Linux started out as the personal project of a Finnish student, right? By the time it attracted the attention of folks other than hardcore nerds, it was the late 1990s and Microsoft had made sure that Windows was utterly entrenched on desktop PCs. Also, while Linux long ago got about 90 percent of the way to being an operating system so intuitive that just about anyone can use it without much training, the last ten percent has proven to be a major challenge.
Random factoid: Linux's omnipresent penguin mascot, Tux, was designed by Larry Ewing as an entry for a 1996 Linux contest. It didn't win.
Underdog to: VHS, the competing format championed by JVC -- which was originally supposed to play underdog to Betamax.
Notable virtues: Every serious video aficionado I knew back in the day favored Betamax. (Which didn't stop me from buying a VHS recorder when I plunked down my money in 1985.) Beta had better picture quality; it had hi-fi sound first; the machines were well engineered. I know folks who still pull out their players from time to time.
What made it an underdog: I'd pin most of the blame on running time-Beta started at an hour, and while it later increased, VHS (which used a larger cartridge) was always a step ahead. I remember the era when some prerecorded movies came out on one tape for VHS but required two for Beta. And far more companies made VHS players than Beta ones, helping to popularize the format and driving prices down. Betamax had a successful low-key second life as a professional standard, but it became an underdog so quickly in the consumer market that it remains a synonym for "superior technology beaten by inferior rival" to this day.
Random factoid: Betamax's great achievement may have been legal rather than technical -- when Disney and Universal sued Sony over its VCR's potential for copyright infringement, Sony won, establishing consumers' right to timeshift TV broadcasts. We could use a similar victory or two today in cases such as this one.
Underdog to: Intel, the inventor of x86 and the company whose products hold most of the other 88.5 percent of the market.
Notable virtues: Has sometimes made processors that trumped Intel's offerings in performance (the original Athlon and Opteron come to mind); even when it hasn't, has provided competition that has played a huge role in increasing the technological sophistication of PC processors and driving down their price.
Why it's an underdog: AMD would tell you it's at least partially because of unfair tactics by former partner and eternal archrival Intel (which it sued in 2005 on anti-trust grounds). New York Attorney General Andrew Cuomo apparently agrees. Other factors: Conservative consumers and corporate buyers who believe (mistakenly) that there's something inherently more compatible about an Intel chip than an AMD one, and the fact that Intel CPUs are by far the most lavishly-marketed components ever to sit inside a computer. And maybe the fact that AMD's core business is making chips compatible with the x86 standard that Intel devised means its DNA is that of an underdog.
Random factoid: AMD produced its first Intel-compatible processor in 1975, so 2010 will mark its 35th anniversary as an underdog.