All versions of Apple's XNU kernel that include DTrace, tagged and imported.
Requests for discussion, based on the idea from Joyent which is based on RFCs from the IETF
Non kernel components of DTrace on Mac OS
Scripts for managing the OpenDTrace project
The DTrace Toolkit: A set of scripts for use with DTrace on various systems.
FreeBSD src tree
Community developed and maintained version of the OS/Net consolidation
dtrace for linux - kernel driver and userland tools
A collection of scripts that work with DTrace
DTrace for Windows OS