DTrace kicks ass. Everyone knows I love ZFS, but in my opinion DTrace is the most significant and disruptive systems technology in at least 10 years. Today I gave my talk at ApacheCon; it was well received. I hope that I inspired some people to go use DTrace and look in their systems' underpants. Here are my slides and the scripts I used for my live demo. I'll update this entry with the video as soon as I have the link.