To elaborate on this, Vulkan is an open _standard_ whose many implementations (user mode driver) may or may not be open source. Vulkan is just a header file, it's up to the various independent hardware vendors (IHVs) to implement it for their platform.

Also a small correction: Vulkan actually _does_ run Apple platforms (via Vulkan-to-Metal translation) using MoltenVK and the new KosmicKrisp driver, and it works quite well.

> Vulkan is an open _standard_

That too kinda depends on where you draw the line, the spec text is freely available but all development happens behind closed doors under strict NDA. From an outsiders perspective it doesn't feel very open to get completely stonewalled by Khronos on the status of a feature that debuted in DirectX or CUDA well over a year ago, they won't even confirm whether it's on their roadmap.

Sure, that's true and a pretty valid criticism of the system.

My definition of open is that Khronos doesn't restrict (as far as I know) what platforms Vulkan can be implemented on. The same cannot be said for DX12 or Metal.

DirectX 12 headers seem to now be published under the MIT license, so I don't see a real difference from a "who is allowed to implement it" perspective.

> Also a small correction: Vulkan actually _does_ run Apple platforms (via Vulkan-to-Metal translation) using MoltenVK and the new KosmicKrisp driver, and it works quite well.

I think, since they mentioned some enterprise deployments on Windows won't have Vulkan drivers preinstalled, that drivers merely being available is not enough for GP to count them as Vulkan "running". I think GP is only counting platforms (and circumstances) where you can reasonably expect Vulkan support to already be present.

Fair enough! In my humble opinion those specific circumstances outlined are a bit overly-pedantic for the target audience of this article and for general practical purposes. The average Windows user can reasonably expect that they'll be able to write a Vulkan application without much fuss ( until you run into the driver bugs of course ;) ).

Vulkan also runs on Apple Silicon without translation on linux

It actually requires translation everywhere. GPUs have their own internal API that Vulkan, OpenGL, DirectX, etc. translate into. That is what drivers do.

That's being disingenuous. Of course a high level api has to be implemented in terms of hardware specifics, but you're implying, hopefully unintentionally, that that hardware interface is Metal, and it's not.

You can run Vulkan on Apple Silicon as natively as you can run Metal, even if some parts of it don't map too nicely to the hardware.

We only seriously say translate when we go from one high level API to another, just like we call some compilers transpilers even though literally everything is a compiler for something.

If you're going to claim MoltenVk = Vulkan on Mac then you might as well claim Wine / Proton = DirectX on Linux.

Not really! The difference is MoltenVK (and now KosmicKrisp) is officially supported and funded by Khronos itself.

DXVK, vkd3d on the other hand is propped up by dozens of passionate open-source contributors.

I'm drawing my lines not based on technicalities, but on the reality of the situation when it comes to how much the "controlling entity" of each API cares about supporting your platforms. And the fact is, Khronos has put time and money into supporting more platforms than Microsoft has.

The Vulkan specification is Open Source. Many Vulkan implementations are not.

Vulkan also isn't built on D3D at all, and only MoltenVK (an open-source implementation for Apple platforms) is built on Metal. (Edit: It appears Mesa also now has KosmicKrisp as a Vulkan translation layer for extremely recent (≤5 years) Mac devices.)

> WebGPU is available as both a C++ (Dawn) and a Rust (WGPU) library.

WebGPU is implemented by both a C++ library (Dawn) and Rust crate (wgpu-rs), but like Vulkan, is itself only a specification. Also I'd still hesitate to even call wgpu-rs an implementation of WebGPU, because it's only based on the WebGPU specification, not actually an exact conforming implementation like Dawn is.

> Vulkan is also not really cross-platform any more than DirectX .

Sure it is: DirectX makes assumptions that it's running on Windows, and uses Windows data structures in its APIs. Vulkan makes no such assumptions, and uses no platform-specific data structures, making it automatically more cross-platform.

Sure, users of DirectX can be cross-platform with the use of translation layers such as Wine or Proton, but the API itself can't be ported natively to other platforms without bringing the Windows baggage with it, while Vulkan can.

Additionally, Vulkan provides a lot more metadata that can be used to adapt to differing situations at runtime, for example the ability to query the graphics devices on the system and select which one to use. DirectX did not have this capability at first, but added it two years after Vulkan did.

Depends on which extensions, things is with Khronos APIs people always forget to mention the extension spaghetti that makes many use cases proprietary to a specific implementation.

DirectX also suffers from it, to a lesser degree. There are important HLSL intrinsics that are vendor-dependent ( https://github.com/Microsoft/DirectXShaderCompiler/wiki/Wave... or https://github.com/NVIDIA/nvapi/blob/main/nvHLSLExtns.h ).

Microsoft used to be more proactive. It pressured vendors to have rough feature parity with each other and then released the "harmonized" baseline as the next DirectX version. But as with many things, Microsoft dropped the ball there. The most recent DirectX revision is more than 4 years old, and it doesn't look like there's going to be a new one any time soon.

The only truly unified API is Metal, for obvious reasons.

Agreed, and your had a more easy example at hand, XBox DirectX, versus the PC world.

The point is that many that argue Khronos APIs are portable, don't seem to have deal how portable they actually are in practice, just like POSIX is portable only to certain extent, or Web standards (which then many just ship Chrome with their app).

> Vulkan is also not really cross-platform any more than DirectX. [...]

Vulkan is not entirely cross-platform, but it's still way "more" cross-platform than DirectX by your own point of view.

DirectX: - Windows - Xbox

Vulkan: - Linux - Android - Windows - Nintendo Switch - Nintendo Switch 2

Metal: - MacOS - iOS

> It claims WebGPU is limited to Browsers. It is, not. WebGPU is available as both a C++ (Dawn) and a Rust (WGPU) library. Both run on Windows, MacOS, Linux, iOS, and Android. It is arguably the most cross platform library. Tons of native projects using both libraries.

I feel like it's important to mention that WebGPU is a unified API on top of whatever is native to the machine (DirectX, Vulkan or Metal).

At least Vulkan runs on Windows, that certainly makes it more cross-platform than DirectX. According to Google, some VNCs on Linux don’t support Vulkan, but I don’t think that’s a fair reason to suggest Vulkan doesn’t run on Linux in general, right? You’re right Vulkan isn’t part of the OS. Does that usually matter, if most people get Vulkan support through their driver?

Also all Khronos APIs have endless extensions, many of which are proprietary and never made part of core, thus many applications cannot be ported across graphics card vendors or operating systems.

Playstation also doesn't do Vulkan, even though people routinely say otherwise.

Also while the Switch does OpenGL and Vulkan, it is really NVN what everyone that wants to get all the juice out of it uses.

> DirectX runs on 2 platforms (listed in the aritcle). Which ones?