Apple's OS X 10.5 Leopard receives UNIX 03 certification

Apple has now joined the exclusive ranks of Sun, IBM, and HP as one of (now only) four companies to obtain the UNIX 03 certification. This means that, with the new OS, Apple has transitioned OS X from being a UNIX-based operating system to actually being the first real official consumer desktop version of UNIX. The certification is actually quite important for Apple and for the OS. The UNIX 03 certification means that Leopard conforms to the Single UNIX Specification Version 3 (SUS), a specification for how things like the shell, compiler, C APIs, and so on should work. This is important for Apple in the enterprise market as it allows its applications to be simply recompiled to run on other RISC-based processors and vice-versa. This makes it easier for companies to transition to Apple's XServe server hardware.