monline

DTrace is a modern tracing framework developed by Sun and now ported to Mac OS X and included in Leopard. The vast potential of DTrace can be exploited through a simple scripting language named "D". There's a very good tutorial on "Exploring Leopard with DTrace", a DTraceToolkit containing a bunch of advanced DTrace scripts and DTrace Scripts, a site dedicated to such scripts. DTrace is a huge leap forward in system profiling and performance analysis, and once you've dived into the subject, you'll find out how much more you can do with it.