> They ditched that once Rosetta support on ARM Macs was good enough to run x86_64 VMs, as apparently all they cared about was supporting Docker on Macs...

Was a research project gone out of hand, arm64 macOS wasn't on the radar and the IoT product it was released for didn't succeed.

> I think it is essentially "complete drawbridge", too. I haven't played around with it in a while, but from memory, you can coerce it to run arbitrary Windows executables, basically anything without graphics (which are missing from the PAL they ship).

sbtrans (for arm64) was static binary translation only. No JIT fallback whatsoever.

> It's quite impressive, though also necessary if you think about it. SQL Server requires the legacy dot net stack,

The arm64 sbtrans-based version had that gone too, and it didn't have a nice engineering path towards supporting those. It'll come back later though I'm pretty sure, with using a more native arm64 version (or arm64EC which exists nowadays)

> AND it also ships with a full copy of the msvc compiler/linker! Not sure if that's ever used by the Linux port, but it is installed. MSSQL kind of exercises every inch of the Windows API surface.

Yes that's used for dynamic query optimisation. It was disabled in Azure SQL Edge for arm64 as that was a JIT-less translated version.