[quote="mistschaufel"]I am not familiar with Darwine, but if is basically qemu, which is just a kernel mod to emulate hardware and not software, you would need to install an operating system.[/quote]
Qemu works in two ways. One is the full system emulation you're thinking of. The other is similar to the way Rosetta works. Both ways are completely userspace (unless using the accelerator). Quoting the Qemu site:
[quote]
QEMU has two operating modes:
[list]
Full system emulation. In this mode, QEMU emulates a full system (for example a PC), including a processor and various peripherials. It can be used to launch different Operating Systems without rebooting the PC or to debug system code.[/list:u]
[list]
User mode emulation (Linux host only). In this mode, QEMU can launch Linux processes compiled for one CPU on another CPU.[/list:u]
http://fabrice.bellard.free.fr/qemu/about.html
[/quote]