DTrace is Sun Microsystem's dynamic tracing framework that allows developers to instrument a program with probes that have little to no effect on performance when not in use and very little when active. Probe data can be collected with scripts written in D (no, not that one). Mozilla DTrace support has been added by the Sun DTrace team and can be used on Solaris 10 and Mac OS X 10.5.
DTrace has been largely supplanted by the Gecko Profiler and other tools, so this documentation has been archived. If you find that there are still use cases of consequence, you're welcome to file a documentation bug.
The DTrace probes currently built into the codebase may be enabled by default in the future, but for now you'll need to create a build with
--enable-dtrace (on Mac OS X you also have to use at least the 10.5 SDK for
--with-macos-sdk, unlike the common configuration that uses the 10.4 SDK).
Trunk nightly builds with shark support (*-mac-shark.dmg here) are built with