The person who became known on the Internet for yelling at servers is now becoming famous for another, somewhat related, feat, creating a new type of data visualization for characterizing system performance. Brendan Gregg, lead performance engineer at cloud provider Joyent, has developed a visualization technique called a flame graph that can be effective for charting how system resources such as CPUs and memory are used. It has subsequently been picked up by a number of engineers who have used it to enhance popular diagnostic tools such as DTrace and Windows XPerf.