Independent game developers (Indies) have been around for as long as game development has been around.
We hear people tossing the "indie" term around, but what does it really mean? My answer will probably surprise you, and possibly make a few people angry.
Note that the term Indie can apply to anyone, not just game developers
Indies are independent, which could mean that they don't have any big sponsors or investors.
Most game engine development licensors use the term to mean "low income" when they use the term "Indie License". "If you make less than $x amount, you qualify to use the Indie license."
A lot of people use the term "Indie" to mean bootstrap, which is another way to indicate that they don't need outside investment.
Other people use the term as a synonym for "hobbyist" and an antonym for "professional", which I have always found insulting.
Indies are generally smaller development shops. The big studios usually work on big projects that can take many months, probably even a couple of years or more, and that kind of development requires a lot of money.
But, I don't think that encompasses the whole meaning of being an Indie.
To grok "Indie", you have to have a deeper understanding of freedom and independence. For some of you, this statement is all you need:
Indies Keep What They Create
It doesn't matter how big or small your studio is, if you can walk away at any time and take everything you created with you, you are an Indie.
That doesn't mean that the others that have worked in the studio can't also keep what you created, with some sort of agreement on joint ownership.
As long as nobody can take away your rights to what you create, even if others also retain some form of co-ownership of those rights in exchange for some sort of pre-arranged payment, then you are an Indie.
Plenty of nay-sayers out there will claim "but that will never work", and give some sort of outrageous edge case to which nobody would ever agree in the first place. Ignore the nay-sayers… it's what they do.
Most people who vehemently disagree with this definition of Indie, and who disagree with this concept of keeping what you create, are either suffering from Capitalism Stockholm Syndrome, or they're interested in making money off the labor of others.
My definition of Indie is not mainstream by any means, but can you imagine living in a world where everyone has the opportunity to be an Indie?