On 24 May 2010, at 18:29, Torbjorn Granlund wrote: > See also http://gmplib.org/macos.html for information about some Xcode > quality problems. The Mac OS X native executable file format is Mach-O. Is that what you mean by a variant of the a.out format? - The latter is for UNIX like kernels, and the for the Mach kernel. Hans