What makes a unix Unix? (Score 1)

What percentage of Apple Applications can Yellow Dog [Linux] run without installing the Apple OS? If it's less than 50%, then I can't think of it as a *nix. If it's more than 75%, then it's clearly a *nix variation. In between is ... in between.

Actually, the way I reason this is if OS X can run nearly everything that will compile and run on Free-BSD (its nearest Unix relative), then OS X is a unix. That OS X can run more than merely what is available for Free-BSD is an advantage rather than a limitation.

The core of Mac OS X is BSD Unix with a Mach microkernel. This means it will run anything that will compile on your favourite flavour of BSD and many things that will compile on Linux and Solaris. You can run Apache, Tomcat, PHP, or your favourite open-source service on OS X. In addition, one may run Office and Photoshop in addition to these fine Unix applications.

For those of us Unix geeks who prize getting work done rather than merely working, Mac OS X is an ideal choice. For example, I can fiddle with .rc files to turn on sshd; or I can simply check a box in the Sharing control panel to turn it on. For many, that's the hallmark of the Mac OS: getting work done however you feel comfortable.