This week KernelTrap interviews John Levon, the author of OProfile and a contributer to KernelNewbies. He offers much insight into both of these projects, as well as reflecting on Linux in general. OProfile is a statistical x86 profiling system for the 2.4 Linux kernel, useful in understanding what percentage of the CPU is being utilized by different processes, including those in kernel space and those in user space. KernelNewbies is an excellent resource for people looking to understand the Linux kernel, comprised of a web page, an IRC channel, and a mailing list.