Up to what point can an OS design and theme mimic another operating system?

Question

I am wondering to what point can the desktop theme imitate another, without being sued for copyright violation or plagiarism. Are there any commonly accepted rules in the jurisprudence of what is and is not allowed?

Let's take for example the Linuxfx distro, which themes are imitating those of Windows 10 or Windows 11: https://www.linuxfx.org/

The graphical interface looks very close from the one of Windows.

Some softwares like Microsoft Edge are available for Linux. So, it is perfectly normal that the exact icon of this browser displays in the interface.

But there are other aspects that surprise me more. When looking at screenshots, the Windows "Start button" icon at the bottom left looks the native one (or very close). Some icons, the inner layout of Windows, texts, colors and even the desktop background look identical or at least very similar.

As a software is a whole, there is work associated with its design, how can a distro like LinuxFx and its Windows themes exist without being sued by Microsoft for plagiarism / copyright infringment?

Answer 1

how can a distro like LinuxFx and its Windows themes exist without being sued by Microsoft for plagiarism / copyright infringement?

It's Microsoft's choice to either sue for copyright infringement or ignore the infringement.

Microsoft would weigh the cost/benefits of a lawsuit that would hinge on the judge/jury deciding the fairly gray area of what constitutes enough infringement for LinuxFx be liable and result in damages for Microsoft.

Would a judge/jury rule in favor of what Microsoft sees as design and copyright infringement? Or would Microsoft lose and end up with bad PR after spending a lot of money?

Or, as ohwilleke mentions: LinuxFx and Microsoft may have a license agreement, so there could already be a legal agreement that LinuxFx can legally "copy" the Microsoft interface.

Answer 2

There was a major lawsuit over this in the early 1990s, Apple v. Microsoft. Apple sued Microsoft for allegedly copying the look and feel of the Apple Macintosh in Microsoft Windows.

The court ruled in favor of Microsoft (internal citations omitted).

Under the law of this [Ninth] Circuit, an article which has "any intrinsic utilitarian function" can be denied copyright protection "except to the extent that its artistic features can be identified separately and are capable of existing independently as a work of art." The very purpose of a computer user interface "lies in its ability to help people prepare and analyze their work quickly and flexibly." Copyright protection can attach only to such a product's separate artistic features or can afford only such limited protection as appropriate when its features are the product of a compilation.

The similarity of such functional elements of a user interface or their arrangement in products of like kind does not suggest unlawful copying, but standardization across competing products for functional considerations. Standardization of the visual features in a computer's interface helps to achieve its purpose, a point which Apple learned early on when it insisted on interface uniformity for Macintosh applications and which has also been implicitly recognized by this court.

The distribution you link to do indeed look more similar to Windows 11 than Windows 2 did to MacOS. It’s possible that Microsoft figures a lawsuit wouldn’t be worth it. (Maybe because the distro wouldn’t be able to pay damages if Microsoft won.)