I have been a mostly faithful mac user since 2003 when I got my first Mac (an eMac). It shipped with 384 MB memory, an 800MHz G4 proc, a 40GB HDD, a CD-ROM drive that I had swapped for a combo—then eventually SuperDrive.  That Mac saw Jaguar, Panther, and Tiger, and like all versions of Mac OS X are based on a the same core, Darwin—a Unix like core operating system based on FreeBSD, and it points out how well Apple gets OS X to scale to meet the hardware requirements.  That Mac was relatively well-equipped with 384MB of memory (for the time), however now, at least is my experience with Leopard, 384MB is less memory than the kernel_task process uses, let alone today’s Adobe AIR based Twitter clients (at almost 500MB for Twhirl).

I think it’s interesting how Mac OS X is so robust that it natively runs on a processor as primitive as the G3 while still being able to run on a modern SSSE-enabled Intel Xenon. Given that Apple has a lot of deep, dark voodoo going on under the pleasant Aqua interface, it still gives credence to the abilities of Unix.

As a special note, today, Apple announced that Snow Leopard is available for pre-order and will ship (in-store and pre-orders) on August 28 (2009)-and this is the first version since Mac OS 7.1.2 to not support any PowerPC-based macs.