Not being an enterprise IT guy, this story went a little past me, but it's apparently big news to some. With Leopard, Apple has now joined Sun, IBM, and HP
as the only four OS vendors to achieve UNIX 03
certification. This is significant because it opens up some interesting possibilities for Apple in enterprise applications once XServes with Leopard Server ship (presumably in October). It's likely that third-party UNIX enterprise software vendors will now be more willing to write for (or port to) OS X. Further, as the InfoWorld article
notes, this will make it possible to code for the Mac and easily port "to RISC big iron" just by recompiling. I suspect this will also make a lot of folks in academia happy as well.