[lenkite]

But Google did NOT copy the open source implementation. Google copied parts of the closed-source proprietary Java SE API specifications in order to have compatibility and without taking a license. Kindly remember that Android started using OpenJDK very late - around 2015–2016.

Legally the case was about copying declaring code from a proprietary product, not an open source one.

[cwillu]

And they lost, because it was fair use, which was obvious to most people in the field. The fact that the lawsuit happened in the first place is why I will never trust Oracle.

[lenkite]

It was not all that obvious from a legal point of view. Google vs Oracle was the first US Supreme Court case directly testing whether copying API declarations can violate copyright. It was also decided later in the EU as well in that SAS vs WPL case where the EU Court of Justice finally ruled that software functionality, programming languages, and file formats are not copyrightable.

These famous cases set the legal tone for the entire world actually.

[TimTheTinker]

Yes - this.

The implications of a judgment in favor of Oracle were staggering. Any codebase that is extensively dependent on a proprietary API is legally locked in to using that company's proprietary implementation as long as that company asserts copyright on its API. Anyone who implements the same API to offer a drop-in alternative to the proprietary product is infringing -- even if a someone privately reimplements the API without distributing the reimplementation.

Which immediately implicates WINE (Windows), Mono (.NET), ReactOS (Windows), Darling (macOS/Darwin), GNUStep (Cocoa/OpenStep), Anbox (Android), Ruffle (flash), GNU Octave (MATLAB), Mesa 3D (Direct3D), ZLUDA (CUDA), and DXVK (Direct3D 9/10/11), to name a few of the most popular...

[vrighter]

But they didn't copy code. Because the code was proprietary and they didn't have access to it.

Reimplementing an interface != stealing code.