Source code for the x86 and PowerPC OS X (Darwin) kernels have been merged in Leopard for the first time. Prior to Leopard, PPC and x86 source trees had to be downloaded and managed separately. Now instead of building the right tree for your system type, you identify your target architecture at build time.The Darwin sources now self-build a bootable Darwin using only make. Previously, you had to download a separate set of build tools called Darwinbuild.x86 and PowerPC aren’t the only targets for the Darwin kernel. The build example in the xnu README attached to the Leopard kernel makes reference to a Freescale MX31ADS ARM9 eval board (link to PDF manual) build target. That bodes well for the reach of the iPhone/iPod Touch developer kit in February, eh? Software Development