Unrelated but this reminds me of temporal pincers from Tenet

How can that be proven? E.g. how can you prove legally that the team writing the code didn't see reverse engineered code?

How can anything be proven in a court of law? You use evidence of the same sorts as in any other litigation process. Testimonies, documents, emails, anything of record. Looking at the result and seeing if it is plausible that what they say is true or not. There is no 100% proof, but there never is in legal proceedings.

Wow. Do you have an example of this happening?

When Accolade Games reverse engineered the Sega Genesis (Megadrive) in the early nineties they employed the clean room technique with two groups of engineers. They went on to produce games for the Genesis without paying a royalty to Sega.

The BIOS used in the original Compaq machines is the classic example of this.

Exactly the example I was thinking of. It was a turning point for Microsoft in the David vs Goliath (IBM) story. Now their software could run on IBM-compatible hardware opening the floodgates for PC manufacturers

ReactOS, an implementation of Windows.

https://en.wikipedia.org/wiki/ReactOS#Internal_audit

Here's a recent HN post about Adobe Type 1 fonts:

https://news.ycombinator.com/item?id=26107659

I cant remember the name, but there was a GNU replacement for flash, I believe one of the rules to contributing was that you had not ever even used Adobe Flash before.

Back around 2007 I used it for a while, it mostly worked okay but always came across things it wouldn't work with and went crawling back.

Wasn't it called Gnash if i'm not mistaken?

The Phoenix BIOS example someone mentioned elsewhere. https://www.computerworld.com/article/2585652/reverse-engine...

I think this is kinda what the Wine project is doing.

I thought in order to copyright code, you need to disclose the source code as part of the registration process, no?

I am not a lawyer but copyrights are automatic rights. Patents follow a process similar to what you're talking about.

Copyright is automatic and grants full protection from the moment of creation.

Registering copyright isn't necessary, it is helpful though in resolving certain disputes. Registration also does not require you to disclose the work to everyone, it requires you to deposit the work with the copyright office, which will pull it out if some court case requires it.

To add to this, in the US, registering is also necessary to sue for infringement (since the 2019 Fourth Estate ruling in SCOTUS) and it determines if the statutory damages apply or not - registration must come before infringement. It's not at all required to file a takedown notice, though.

My understanding is that registration is not required before infringement occurs, but it is required before a copyright lawsuit can proceed. That is, any lawsuits with regard to a unregistered copyright will be paused until the copyright is registered.

The lawsuits regarding unregistered copyright are and were expressly forbidden under Copyright Act of 1976 - 17 U.S.C. 411 [0] (with the specific exception for the case where all procedures were met, but registrations has been refused), but some districts used to consider the mere filing of the papers as sufficient to sue under, and some did not. SCOTUS resolved it in the Fourth Estate case by reaffirming that you are required to hold a registration of the work to sue for copyright infrigement of that work. [1]

THe "infringement before registration" does not affect the ability to sue for it - it only affects the ability to get statutory damages [2], which is where the huge figures are coming in, as you do not have to prove actual damage - but it does mean that any lawsuits filed before registration is obtained are to be dismissed due to lack of standing and of course statute of limitations also applies.

There are some othe exceptions but they consider unpublished works and/or works within 3 months from publication, so they don't often come into play.

[0] https://www.govinfo.gov/content/pkg/USCODE-2010-title17/html...

[1] https://supreme.justia.com/cases/federal/us/586/17-571/

[2] https://www.govinfo.gov/content/pkg/USCODE-2010-title17/html...