Notes:
Advantages over xscope:
Can choose which requests to trace, reduces performance impact and lessens overwhelming amounts of data from large applications
Can start tracing running application without having to restart it via xscope proxy display
Can combine with other probes to trace effects across programs and in kernel
Disadvantages:
Only available on Solaris so far
Dtrace source has been released under CDDL (based on MPL), but would take a lot of work to integrate into another kernel
Requires root access or for root to grant dtrace privileges