The DTrace Dynamic Tracing Framework
This is the Linux port of
the Solaris Dynamic Tracing Framework.
It is composed of two portions, a kernel portion, and a userspace portion.
The kernel portion is built into the UEK kernels and is also available on a public git tree.
The userspace tools are available from OTN and git.
The latest release, for x86, based on UEK kernel 4.1, is version 0.6.1, released on 28 Sep 2017. It will also be available from OTN.
The license for DTrace has changed over time. Versions before 0.6.1 include a CDDL kernel module and a proprietary userspace component; versions 0.6.1 and above have a GPL kernel component and a UPL userspace component.