> Nobody's saying it can't be developed without Windows
The first sentence of the link: "Cosmos (C# Open Source Managed Operating System) is an operating system development kit which uses Visual Studio as its development environment."
At another point in the article: "Cosmos lets you create operating systems just as Visual Studio and C# normally let you create applications. Most users can write and boot their own operating system in just a few minutes, all using Visual Studio. Since milestone 5, Cosmos includes an integrated project type in Visual Studio and an integrated debugger. You can debug your operating system directly from Visual Studio using breakpoints."
And that's fine. Visual Studio is, as I've heard, an excellent IDE. But Visual Studio is indeed a Windows-only thing, for the foreseeable future.
In addition, elsewhere in the article it is mentioned about this project that the developers "want to make developing operating system as easy as developing Windows applications". That is clearly a bias towards the way of developing on Windows only.
And again, that's fine too.
But all this also agrees with my statement that it "cannot be developed without using Windows" in a practical sense. Sure, I could build my own, as you say, but that would be in conflict with the way the project's developers want it to work.
The project might be configured to build with Visual Studio but there are other C# compilers available. And Visual Studio is available for macOS in addition to Windows. https://www.visualstudio.com/vs/mac/
> The first sentence of the link: "Cosmos (C# Open Source Managed Operating System) is an operating system development kit which uses Visual Studio as its development environment."
Sorry. Sloppy antecedent. It being an "operating system construction kit," not "it" being Cosmos.
Barring active dangers such as security malpractice it is absolutely, positively shitty to neg somebody's freely-made-available public contribution because you don't like the OS it runs on (and I don't; I don't have a Windows development environment myself!). They're doing it for free and they're not doing it for you. If you want it done your way, you do it; I'm sure they'd happily accept contributions that enabled it to run outside of VS on other OSes and the underlying runtimes that Cosmos uses seem to be available on Mac and Linux.
I think you're stretching my original comment a bit too far.
I didn't say the project is bad. I commented that the situation is a bit unfortunate. There's a difference between that and "negging somebody's contribution".
> If you want it done your way, you do it
To be clear, I've seen this argument made about lots of open source projects, and it's always discouraging to discourse. Sometimes that's intended, but I think in this case — as in most — it's merely neither here nor there. As you can see by my grandparent comment, I have nothing against the authors building their project however they like. In fact, if I demanded that they change the way it's done, that'd be in line with what you're accusing me of. I did no such thing.
> I'm sure they'd happily accept contributions that enabled it to run outside of VS
The entire point of my grandparent comment was to show how the article strongly suggests that's unlikely. And again, for the third time, that's absolutely fine. As fine as the unlikelihood of the Linux kernel allowing contributions in Rust, or even C++.
I'm not complaining. I'm just pointing out your misreading.
The first sentence of the link: "Cosmos (C# Open Source Managed Operating System) is an operating system development kit which uses Visual Studio as its development environment."
At another point in the article: "Cosmos lets you create operating systems just as Visual Studio and C# normally let you create applications. Most users can write and boot their own operating system in just a few minutes, all using Visual Studio. Since milestone 5, Cosmos includes an integrated project type in Visual Studio and an integrated debugger. You can debug your operating system directly from Visual Studio using breakpoints."
And that's fine. Visual Studio is, as I've heard, an excellent IDE. But Visual Studio is indeed a Windows-only thing, for the foreseeable future.
In addition, elsewhere in the article it is mentioned about this project that the developers "want to make developing operating system as easy as developing Windows applications". That is clearly a bias towards the way of developing on Windows only.
And again, that's fine too.
But all this also agrees with my statement that it "cannot be developed without using Windows" in a practical sense. Sure, I could build my own, as you say, but that would be in conflict with the way the project's developers want it to work.