"Open Source" gets weird with physical objects, though, since functional elements aren't covered by the copyright system software licenses rely on. Copyright would apply to decorative elements and the name plus trademark on the name, but unless there's a patent the functional elements are public domain.

Yeah, it does. To be clear, I'm only referring to the license of the files themselves. In absence of a patent or trademark, the "system" is effectively unlicensed. So, "free" might be a better descriptor anyway.

One of these days we may get same terminology around open source stuff, though I suspect that's the same day hell opens an ice skating rink.

2) It's open source, as in software with an open source. But it's not “OSI Certified” open source software.

The term “open source” is not trademarked. It's high time well-meaning people stopped appropriating the term and pedantically corrected people who use the term outside of their own narrow definition.

Gridfinity is source-available, not open source. The commonly accepted definition of open source includes the freedom to redistribute without discrimination against certain types of use.

For me, open source means that sources are available to the end-user, that's all. What you describe is free software (as in freedom). Open source is typically also free (as in freedom/libre) and free (as in beer), but it is not always the case.

Here is an article by Richard Stallman about the difference between free and open source: https://www.gnu.org/philosophy/open-source-misses-the-point....

The page you linked to clearly states that "open source means that sources are available to the end-use, that's all" is a misunderstanding:

> However, the obvious meaning for the expression “open source software” is “You can look at the source code.” Indeed, most people seem to misunderstand “open source software” that way. (The clear term for that meaning is “source available.”) That criterion is much weaker than the free software definition, much weaker also than the official definition of open source. It includes many programs that are neither free nor open source.

Stallman then advocates for the term "free software", which he says would avoid this misunderstanding. A more comprehensive summary of the history of the terms "free software" and "open source software" can be found on Wikipedia: https://en.wikipedia.org/wiki/Alternative_terms_for_free_sof...

According to the FSF, the only software that is open source but not free is "tivoized (tyrant) devices" which "contain nonfree executables made from source code":

> Among all programs that are open source, only a minuscule fraction are not free. If the bottom row were drawn to scale, its text would have to be in a tiny font, perhaps too small to read.

https://www.gnu.org/philosophy/free-open-overlap.html