Re: Now end Windows
[Author here]
> WSL1 literally was an NT kernel personality
That is what I thought myself, and I said so in an article. A lot of Microsofties got very angry with me on Twitter, published various insults and threats and no citations or evidence at all. To their shock and bafflement I rejected their arguments from authority and refused to back down until they refuted me: meaning, provided evidence that I was wrong.
Which, to be fair, they reluctantly did, linking to various internal MS documents, presentations and things which I had been unable to find from web searches.
To cut a long story short: no, it wasn't. It was unrelated to the NT POSIX personality except inasmuch as it came from the same company, a quarter of a century later.
A fairer summary of WSL1, as far as I can place the history, is this:
1. Some MS exec thought that having Windows Phone able to run Android apps would be useful.
2. Windows Phone being based on NT by then, MS had to develop an Android emulator for Windows NT.
3. This proved harder than anticipated, and a special version of Android's originally-a-sort-of-JVM was not enough.
(Aside: Android 1 & 2 had a sort of JVM. Android 2.2 replaced this with Dalvik, which did JIT compilation. Android 4.4 added a new runtime, ART, which does AOT instead of JIT, as an alternative to Dalvik. Android 5, ART replaces Dalvik.)
So MS had to implement an emulator for the Linux kernel API to support the ART runtime.
4. Since now, after a *lot* of work, MS had a Linux kernel emulator for NT, someone decided to offer this as a new Linux compatibility feature.
5. It worked, but not that well and performance wasn't great for filesystem-intensive stuff. Git is *extremely* FS-intensive. Linux developers love Git.
6. MS introduces WSL2, which discards the emulator and runs a real Linux kernel in a VM.
7. MS discontinues the Windows Runtime for Android. https://learn.microsoft.com/en-us/windows/android/wsa/
Summary:
In my cynical suspicious view, all because some exec with no technical knowledge promised something that turned out to be very hard and became irrelevant once another exec decided to kill Windows Phone, just about the point when it became viable to take an Arm phone, add a keyboard, mouse and screen, and use it as a PC. As a result MS spent about a decade and probably $tens of millions on a futile excursion which is probably one of the biggest OS dev exercises of the century so far.
Summary of the summary:
There are few real deep techies left in authority in MS any more, and decisions are made without proper tech understanding.
Saying that, much the same is true of Apple and indeed the enterprise Linux vendors.