I'd be happy to unblackhole mine if it gets more people involved.
The x86_64 part is because ObjC doesn't provide a completely machine-abstract way to invoke dynamically. Each way has some icky flaws. My first goal was actually iOS, but I went down the x86_64 path because Mikael had a need for that first. I'd like the package to have x86_64/i386/arm.
I did discover that a LOT more machinery is needed for x86_64 than for i386 or arm. Calling conventions on 64-bit are crazy insane (though I now have the worst of it solved).