> The ARM branch mean is possible to do iOS dev on it?

No. You can compile for ARM + a platform (i.e. Linux, BSD) if you want to run Go code on an ARM device. Think RaspberryPi or Beaglebone running an ARM port of Ubuntu/Arch.

Writing Go code targeting iOS (or Android) is a whole 'nother ballgame.

Android is just Linux, Go works perfectly fine on it. Go issues syscalls directly and doesn't use libc for that (it uses glibc for name resolution, but with cgo disabled it doesn't do even that).

Minux did an iOS port, it's not part of the official tree because an iOS port required a rooted device. Perhaps this might have changed as with two word funcs, the Go runtime doesn't do runtime code generation.

iOS is too locked down to properly build Go code for. It's possible to write useful Go code on Android though, Brad Fitzpatrick posted about doing so recently:

https://plus.google.com/115863474911002159675/posts/DWmyygSr...

No, the ARM architecture is only supported on Linux right now (although unofficially it's mostly working on some other platforms too).

I remember reading that Go was ported to darwin/arm, but it can never be supported since there is no way to legally run their test suite for it.

This ticket might interest you: http://code.google.com/p/go/issues/detail?id=837

Maybe one day it'll come. If on that day iOS has gained a public XPC API I'll be quite the happy camper.