Apple is officially moving away from Intel to a custom Arm chip

[Seiji Emery]

addendum:

yes, this means you'd be stuck w/ an apple dev kit (and need to 
be a registered apple developer so the full cost of getting this 
is ~$600)

but this is probably your best bet, by far, for getting a full, 
working developer environment on an arm chipset atm, outside of 
running an old surface tablet w/ windows RT, or running a linux 
distro off a phone, or something.

Apple's implementation of this is running full mac os, with 
probably one of the fastest arm chipsets out atm

And it can run x86_64 code using an emulation layer (which I'm 
guessing is mostly just binary recompilation to arm, or 
something), which... obviously neither of the other two options 
can do afaik

Geekbench, supposedly, is running on it (and w/ the x64 version), 
and it benchmarks pretty darn close to a 4-5 year old i5 / i7 
laptop (source: have a 5 year old laptop w/ an i7 4980hq, and the 
dev kit's benchmarks are shockingly close to that)

it'd be pretty interesting to see if dmd can run on this out of 
the box, and what problems (if any) there might be with that. 
(intrinsics? threading? runtime code modification??)

For porting bits of dmd and/or druntime and/or toolchain stuff to 
arm, I'm not sure you could do better than working on a pretty 
powerful arm chip that can run both arm *and* x86_64 code

You'd be stuck w/ macos ofc, but I'm pretty sure you could do 
quite a bit worse on that front in terms of having a real, 
working desktop development environment, that can run real dev 
tools and w/ performance that will probably not suck. no visual 
studio, but eh, vscode should work (hopefully), and there's 
intellij stuff. and there's xcode, which... if nothing else has 
pretty good debugging and profiling tools, and can be run on d 
binaries if you're sufficiently motivated and/or desperate