Some comparison with D:

> Do I have access to an asm keyword,

Yes, D has a builtin assembler

> or can I easily link assembly files?

Yes

> Do I have access to the linker phase to customize the layout of the ELF file?

D uses standard linkers.

> Does it need a runtime to work?

With the -betterC switch, it only relies on the C runtime

> Can I disable the standard library?

You don't need the C runtime if you don't call any of the functions in it.

Thanks. I haven’t played with D since it also had a closed source implementation (10+ years ago) and never kept up with its newer development. I should check it out again.

I don't get what's up with the runtime hysteria. All languages have a runtime maybe except for assembler. And linux kernel itself is infamous for being not C by a large margin. And in general remove something important from any program and it will stop working.