What is Mac OS X?

This is a fabulous, extremely technical look at all the underlying technologies that make modern Apple Computers and OS X tick.

Topics include “History”, “Architecture”, “Programming”, “Features”, and “Software.”

Some of the more interesting parts:

  • Architecture of Mac OS X Darwin 7.0.x (corresponding to Mac OS X 10.3.x) consists of over 250 packages. Many of these are Apple package (including the Mac OS X kernel and various drivers), while the others originate from *BSD, GNU, etc. Apple ha leveraged a lot of existing open source software by integrating it well (usually) with their system: apache, bind binutils, cvs, gcc, gdb, gimp_print, kerberos, mysql, openssh, openssl, pam, perl, postfix, ppp, python, rsync samba, and many more BSD/GNU/other packages … are all part of Darwin.
  • Booting Mac OS X An Open Firmware implementation is based on the Forth programming language, in particular, the FCode dialec (FCode is an ANS Forth compliant dialect that supports compilation of FCode source to bytecode). Apple and Sun ar two prominent computer system makers that use implementations of Open Firmware in their systems (Sun’ trademark is calledOpenBoot). The Open Firmware Working Group’s home page is hosted at various places, including Apple and Sun.
  • XNU: The Kernel NU’s Mach component is based on Mach 3.0, although it’s not used as a microkernel. The BSD subsystemis part of the kernel and so are various other subsystems that are typically implemented as user-space servers in microkernel systems. XNU’s Mach is responsible for various low-level aspects of the system, such as…

Its a fun read, even if you don’t exactly understand every little thing he’s talking about :)