Indie = independent.
An indie studio IMO is one which is not working for or on behalf of any other company. They have full control over the funding, and full creative control over the project in development. There are no constraints imposed on them by anyone else in any way.
The size of the project and/or the number of people working on it makes no difference to the definition. Nor does the past history of any individuals working on it. As long as everything they're doing is self-contained, without help from outside, and without having to conform to restrictions imposed from outside, they're independent.
That's my opinion, anyway.







