I cannot take the author seriously, as there's no mention of DTrace — which isn't even OS X-specific, as it originated on Solaris, has a good FreeBSD port, and

I cannot take the author seriously, as there's no mention of DTrace — which isn't even OS X-specific, as it originated on Solaris, has a good FreeBSD port, and even some rumored-to-have-once-been-working Linux port attempts. (Didn't work last time I tried them, which was half a year ago.) There's a useful book covering all supported platforms: http://dtrace.org/blogs/brendan/2011/02/23/dtrace-book-sample-chapter-file-systems/ http://dtrace.org/blogs/brendan/2011/02/23/dtrace-book-sampl... DTrace also forms the basis for Apple's Instruments, which the author chooses to casually dismiss: http://developer.apple.com/library/mac/#documentation/DeveloperTools/Conceptual/InstrumentsUserGuide/InstrumentsQuickStart/InstrumentsQuickStart.html http://developer.apple.com/library/mac/#documentation/Develo...