A [Unix] variety. Based on the [FreeBSD] userland and the Mach kernel, with a runtime derived from NeXT's OPENSTEP. Darwin is the kernel name and is modular in approach in comparison to the monolithic nature of Linux. (http://www.apple.com/macosx/ Apple's website) (http://www.opendarwin.org/ Open Darwin) If you are new to Mac OS X, an indispensable guide is (http://www.oreilly.com/catalog/macxmmpanther/ Mac OS X: The missing manual). The other good book is (http://www.oreilly.com/catalog/macxunwire/ Mac OS X Unwired), which covers wifi, Bluetooth and other wireless technologies (eg. IR). ---- Useful Mac OS X wireless tools include: * (http://www.macstumbler.com/ MacStumbler) * (http://www.istumbler.net/ iStumbler) * (http://www.binaervarianz.de/projekte/programmieren/kismac/ KisMac) ---- If you have one of the titanium Powerbooks (the model before the new drool-worthy aluminium models), you might find that the inbuilt Airport reception is average. There are two options: 1. Use a PCMCIA wireless card instead (with an external aerial) 2. (http://www.binaervarianz.de/projekte/hardware/mactail/ Hack your Powerbook to take a pigtail)