I've seen some people tagging games with '
indy' lately (which I assume is misspelling of
indie), but I've not found any good definitions for the term. The only one I know is independently
published (commercial) games. This excludes free(ware) and open source games (the two latter ones would pretty much all be marked as indie if they were allowed, very few of them seem to be funded by larger companies).
I also doubt there's much need for it, not without first defining what belongs to it and what doesn't. Mostly for those who like supporting indies, but I think list of indie developers/companies is more useful for that. And you can't really support them if the games they put up on some website are for free, so there's no reason to identify them beyond that part.
There are currently two games I know to be definitely indie:
Aquaria and
Audiosurf. The difference with both in comparison with the games tagged as indy is that both have been published commercially.
Also, if we follow with current lack of definition, homebrew tag will be useless as they both do the same thing now (I don't like that tag much anyway).

by
Zerothis# 2 months and 6 days ago (updated 2 months and 5 days ago)Indie is anti-conformity that manages to get published either professionally or alternatively and can intend limited profit to massive profit. Indie is usually intended to have mass appeal or appeal to a specific audience. Indie can have any sized budget. It is implied that the author has some choice in conforming or not and decides that not conforming is their proffered option.
Arthouse works aren't created for mass appeal. Generally small budget, limited release. Produced professionally, but for art's sake rather than profit. Conformity is a non-issue for these type of games. Ideally, the artist has direct control in the presentation of the work.
Homebrew is based in conformity. A non-professional author is attempting to conform to the standards of the industry as best as his or her situation allows them to with full knowledge the budget, skills, and/or tools are probably not up to par with or outdated from the current industry standards. Although having an above average or professional level in one or more of these means does occur. It is implied that the author's options are limited by factors that are beyond their control.
I'm posting this here so it can be discussed before the indie tag definition is edited.
There is some room for overlap, and while authors or marketing departments may try to convince others of intent, facts are probably a much better indication. In fact, circumstances might effect more so than intent. And it can be a close call. For example, Prince of Persia for the SAM Coupé. Chris White created a nearly pixel perfect copy of the Amiga version. He sought to conform his version of the game to the Amiga version and did so without the benefit of a large budget, professional tools, teams of skilled programmers, or any of the other advantages that a professional publisher and developer could have provided. Had he simply released it as shareware, or free, or some other form of self publishing, it would have been homebrew (and also illegal, such things do happen). He could have approached the Domark about creating the game, gotten permission, and done it 'the right way'. This is uncommon, but it happens. But only after finishing the game, he approached a professional and official publisher who had the legal rights to publish the game. In truth, they would have not authorized him to even attempt the project if he'd gone through the proper channels first. And if the game was not finished, nor of high quality when he officially approached them, they would nor have authorized him to finish or improve it. This was because the SAM Coupé was officially discontinued and had a minuscule user base. Chris White rightly perceived that by not conforming to the proper industry procedures of game creation, he stood a better chance of getting his work published. And it did get published. Thus an otherwise homebrew game became an indie one.
Shigeru Miyamoto is an author who has often boarderlined on indie in intent but never been factually indie. Games like Pikmen and Zelda were not expected to amount to much by his superiors but he did not yield. He always managed to gain authorization to proceed and has not yet resulted in using any other mean than which Nintendo grants him. I suspect that he may yet publish a game that Nintendo does not provide funds, tools, personal, marketing, or law suits for (they'll 'let him' do his own thing without interference one way or another).
Micheal Cranford approached a different company from the one he worked for in order to create The Bard's Tale. Not indie because he went through the proper channels. And The Bard's Tale II, while programmed nearly exclusively from his home, was also under the official industry umbrella. So its not indie, not homebrew.
Warren Robinette usurped company time and resources and programmed Adventure in secret after explicit instructions not to (he even avoided doing the jobs that were assigned to him). This was indie intent. Yet he was able to eventually gain official support from his boss for the project. Not indie.
To me that isn't very
clear difference. I see much potential for overlapping (or much speculation on the author's intentions if that conform to industry bit is to be believed).