http://www.freebsd.org/marketing/os-comparison.html

[Andriy Gapon]

on 30/08/2011 16:45 Paul Ambrose said the following:
> I do not believe the current status of DTrace is appropriate for promoting
> 
> 1. DTrace is an experimental function  or Semi-finished products. The kernel
> dtrace support is ok, but the userland support is far from completion(at
> least the pid  provider has many bugs)
> 
> 2  the FreeBSD implementation is different from Solaris/Mac OS X. The
> DTraceToolkit, which has many amazing feature, can not 100% works on
> FreeBSD, and there is no doc to identify the difference.
> 
> 3 There is a missing feature list about DTrace, but no schedule list about
> when to fix it.

4. There is a missing developer/maintainer for DTrace on FreeBSD.

Nevertheless the kernel DTrace is quite usable and useful for kernel debugging.

-- 
Andriy Gapon