I received another email from someone on the coreutils list which said that the behavior had changed in a recent build. Sure enough I downloaded and installed the new coreutils-6.9 and now the standard uname and "guname" both report the same things: uname -a: Darwin MacBook.local 8.10.1 Darwin Kernel Version 8.10.1: Wed May 23 16:33:00 PDT 2007; root:xnu-792.22.5~1/RELEASE_I386 i386 i386 guname -a: Darwin MacBook.local 8.10.1 Darwin Kernel Version 8.10.1: Wed May 23 16:33:00 PDT 2007; root:xnu-792.22.5~1/RELEASE_I386 i386 i386 MacBook1,1 Darwin uname -m: i386 guname -m: i386 uname -n: MacBook.local guname -n: MacBook.local uname -p: i386 guname -p: i386 uname -r: 8.10.1 guname -r: 8.10.1 uname -s: Darwin guname -s: Darwin uname -v: Darwin Kernel Version 8.10.1: Wed May 23 16:33:00 PDT 2007; root:xnu-792.22.5~1/RELEASE_I386 guname -v: Darwin Kernel Version 8.10.1: Wed May 23 16:33:00 PDT 2007; root:xnu-792.22.5~1/RELEASE_I386