Unix on Apple
By Joshua Marker
Until recently, anyone in the computer industry would be entirely within their rights to assume you were crazy if you asked about server operating systems from Apple computer. Previously, Apple's only such product was the nearly unheard-of A/UX. But in 1996, Apple bought NeXT, and with it acquired OpenStep, a Mach-based workstation operating system. Apple has spent the intervening years redesigning OpenStep and integrating it with Apple's existing operating system, resulting in the release of Mac OS X last September. Mac OS X Server is the server counterpart to the new Mac OS. The result is a combination of Unix stability and mainstream application support.
Not Your Father's Mac OS
Mac OS X's Unix foundation, code-named Darwin, is a slight variant of the FreeBSD tree, using a Mach 3.0-based kernel that guarantees full buzzword compliance—including protected memory, symmetric multiprocessing, and preemptive multitasking. Open-source pundits will be pleased to learn that Apple has open-sourced the entire Darwin layer. It has even gone as far as hiring Jordan Hubbard, co-founder of the FreeBSD project and member of the FreeBSD core team, to manage Darwin.
The server has two application layers, called Carbon and Cocoa, on top of Darwin. The Carbon layer lets you use classic Mac OS applications. Developers can choose to either leave their applications as they are, requiring them to run in an emulated version of Mac OS 9, or Carbonize and recompile them, giving them all of the buzzword benefits of a full Mac OS X application.
