Some common words include: “open source”, “free”, “libre”, “FOSS”, “FLOSS”, “closed source”, “non-free”, “proprietary”. Which ones do you like to use or not like to use, and why?

Also, I understand that some of them are not the same (e.g. “free”/“libre” and “open source”), but are sometimes used as if they were. How do you feel about that?

I personally like to use the word proprietary. It has a clear definition, even without the need for something like the Free Software Foundation or the Open Source Initiative to provide one. That cannot be said for words like “free” or “open source”. Both “free” and “open” feel very shaky. I can imagine companies allowing very minor and trivial freedoms to users, to justify promoting themselves and their products as “free” and “open”. That might not work on hardcore enthusiasts like me, but it might be enough to confuse the masses and manipulate the public’s understanding of these words. I feel like we should take that more seriously. But maybe I’m just paranoid. Please tell me what you think about this. I am very curious