The bootstrapping story is a little hard to follow here. I think the normal zig compiler has a C backend which was run on itself, the source cleaned up by hand then checked in. Bootstrap then means compiling that generated-then-edited C, with an ongoing obligation to update that C implementation when the language changes.

Does anyone know what the language runtime status is for zig? I think there's a libc involved somewhere. There's a standard library which is probably written in zig, did that also get compiled to C and checked in to support the generated bootstrap compiler?

This post talks about a checked in binary that was compiled from something and will periodically need to be updated. It's unclear whether that allows deletion of the C bootstrap code.

Oh, and there was a C++ implementation as well, which is no more. That does sound like a win.