I've written before about achieving a 300x performance improvement. While that sounds impressive, it was effectively in a lab situation, so it doesn't really count. But now I've done even better than that, and in this case, it was a real-world improvement.
I am not just talking about MacOS X or FreeBSD here. DTrace works great for Solaris versions prior to Solaris 10 as well. In fact, it works great for Linux and Windows too.
