There are fair use carveouts for reverse engineering code to, for example, make it usable on different platforms. I don’t believe this kind of decompile project has ever had its day in court and the laws are written in such a way that the outcome is at least somewhat likely to be skewed in favor of reverse engineering. Nintendo may be avoiding bringing suit because they don’t think they could win or that the judgement might make expanded rights explicit encouraging more of this kind of thing.
Those fair use exceptions only cover the process of reverse engineering specifically. From that article: "Reverse engineers execute code and/or make copies of software as part of analyzing the way the program works."
But distributing the code is not part of the reverse engineering process, so that fair use doesn't apply. Also from that article:
> It is highly risky to copy any code into a program you create as a result of reverse engineering, because that copy could infringe copyright unless it is a fair use under copyright law.
It's even possible that Nintendo evaluates the harm of these projects to be rather lower compared to distributing the complete games themselves. Even though it's not based in any legal reality, the projects' firewall of "You must provide art assets from your own copy of the game" may suffice to keep the lawyers away.
I know, Nintendo will litigate anyone for any reason, but it is possible for a company to look away when these measures are taken.
Yeah, seems most likely. In the past, they've explicitly taken down distributions of things like the SM64 PC port, but left the decompilation.
Companies don't have to C&D. If something poses very little financial danger, but taking it down presents significant risk of PR harm, it's not worth it. The C&D would cost more than it would save, so it makes no business sense.
Don't ask me why they even bothered taking down fan games, though. They seem to care a lot about art assets in particular.
> Don't ask me why they even bothered taking down fan games, though. They seem to care a lot about art assets in particular.
If talking about AM2R, it posed a rather credible threat against the success of the official Metroid 2 remake (ignoring the fact that AM2R is of much higher quality anyway). Plus it contained ripped sprites from Zero Mission, Fusion, and incorporated all of the characters and enemies that Nintendo owns.
You can't just make your own Lord of the Rings or Star Wars without infringing the copyright of the original work. Same with fan remakes.
EFF on the topic https://www.eff.org/issues/coders/reverse-engineering-faq