As everyone said, WSL2 is actually virtual machines and it is what most people are actually using now. That said, I feel the need to chime in and say I actually love WSL1 and I love Windows NT the kernel. It bums me out all the time that we probably won't get major portions of the NT kernel, even an out-of-date version, in some open source form.

I like Linux, and I use Linux as my daily desktop, but it's not because I think Linux or even UNIX is really that elegant. If I had to pick a favorite design it would be Windows NT for sure, even with all its warts. That said, the company behind Windows NT really likes to pile a lot of shit I hate on top of that pretty neat OS design, and now it's full of dubious practices. Automatic "malware submission" on by default, sending apps you download and compile yourself to Microsoft and even executing them in a VM. Forced updates with versions that expire. Unbelievable volumes of network traffic, exfiltrating untold amounts of data from your local machine to Microsoft. Ads and unwanted news all over the UI. Increasing insistence in using a Microsoft account. I could go on and on.

From a technical standpoint I do not think the Linux OS design is superior. I think Linux has some amazing tools and APIs. dmabufs are sweet. Namespaces and cgroups are cool. BPF and it's various integrations are borderline insane. But at its core, ... It's kinda ugly. These things don't all compose nicely and the kernel is an enormous hard-to-tame beast. Windows NT has its design warts too, all over, like the amount of involvement the kernel has in the GUI for historical reasons, and the enormous syscall surface area, and untold amounts of legacy cruft. But all in all, I think the core of what they made is really cool, the subsystems concept is super cool, and it is an OS design that has stood up well to time. I also think the PE format is better than ELF and that it is literally better for the capabilities it doesn't have w.r.t. symbols. Sure it's ugly, in part due to the COFF lineage, but it's functionally very well done IMO.

I feel the need to say this because I think I probably came off as a hater, and tbh I'm not even a hater of WSL2. It's not as cool as WSL1 and subsystems and pico processes, but it's very practical and the 9p bridge works way better than it has any right to.

Thanks for pointing this out.

Put another way: Worse is Better

It used to be. They moved to a VM.

Turns out that it's easier to emulate a CPU than syscalls. The CPU churns a lot less, too, which means that once things start working things tend to keep working.

> Turns out that it's easier to emulate a CPU than syscalls

I don't think WSL2 supports CPU emulation. It might not even support (or at least rely on) driver emulation, though Hyper-V itself does.

You're thinking of the POSIX personality of Windows NT of old. This was based on Interix and has been deprecated about two decades ago and is now buried so deep that it couldn't be revived.

The new WSL1 uses kernel call translation, like Wine in reverse and WSL2 runs a full blown Linux kernel in a Hyper-V VM. To my knowledge neither of these share anything with the aforementioned POSIX subsystem.

WSL 2 is actually virtualized despite the name

WSL1 was a subsystem. WSL2 is mostly a VM.

They had to give that up because it was too slow, I think for IO. Unfortunate.

It's complicated. WSL1 is much faster at accessing the drives mounted in Windows, but much slower at accessing its own emulated drive.

If you have control over where you put your git repo, WSL2 will hit max speed. If you want it shared between OSes, WSL2 will be slower.

It also didn't have working fsync, and corrupted SQLite databases. I think that's more important.

I mean... WINE does the same on windows, but microsoft refuses to release their API docs for all internal APIs. They release WSL by relying on Linux's open-ness, while refusing the same for themselves.

Then they discontinue WSL1 and just do a VM instead because... reasons. I really don’t understand how MSFT works on the inside.

A big one of those reasons was Docker. Docker was still fairly niche when WSL was released in 2016, but demand for it grew rapidly, and I don't think there was any realistic way they could have made it work on the NT kernel.