In the few tests that I have done, LinuxPPC outperformed Darwin for graphics calculations (like rasterization). Still, there is promise for Darwin, which has certain advantages such as, interoperablility with MacOSX and a realtime kernel
Additionally, SMP may be better with Darwin, and I plan to test that soon.
Meanwhile, I have been doing more ports. Here is a list of software that I have ported to Darwin.
gtk-Gnutella, WindowMaker, RXVT, Login.app, and others.
Please visit my Darwin page to see more. Here's the link.
http:// proclus.tripod.com/darwin
Regards, proclus
