By your definition(and no one said "illegal") Activision games are "bootlegs".
The point I was trying to make is that First Star Software endorsed Boulderdash for the 2600, thus making it an "official" release even though no one on their staff coded it. Halo2600 was coded with, I'm guessing, a "gentleman's agreement", as I never heard of there being an actual contract signed(correct me on that if I'm wrong). Of course, it's not like a game released for the 2600 is going to cut into sales of modern games.
Homebrews, in my mind, are games created by independent coders, who don't do that sort of thing for a living. Yes, Boulderdash was a labor of love, just like other homebrews. The difference was the contract between the coders and First Star Software(the copyright holders).
Except for Nintendo, I haven't heard of any C&Ds being issued over Atari console homebrews. So, we can reason that other copyright holders don't feel it's worth the time or money to take legal actions for games on this level.
I know no one said illegal, but it seemed to me everyone was bristling at the mere mention of the word 'bootleg' so I just wanted to let everyone know I wasn't using it as an insult.
Well, those are good points, but even with permission, because they weren't made the companies themselves, or 'in house' if you will, I'd still define that as Homebrew. To me, no payment = Homebrew. See, even there, if Microsoft, First Star, or anyone purchased the rights to the games, my definition gets blurry, kind of the fun of it if you ask me.
I like your definition of Homebrew, I would add those who do it for a living too, as long as the end result wasn't done as part of their job. Like the original Homebrew Computer Club.
And I'm sure if we were to look into public record (or where ever lawsuits are filed and stored, I don't honestly know) we'd find Atari filed a lot of them back in the day. I mean, from what I have seen in interviews and documentaries, its seems Atari and Activision never really stopped suing each other. Then there were other battles with Mattel, who also sued Activision and Coleco in addition to suing Atari, it quickly becomes a mess. I mean, perfect example, the Gemini exists because Atari sued Coleco, who counter-sued with CBS behind them, and they settled out of court and Coleco got a license to Atari's patents.