PSTREE is a clone of the standard Linux pstree command, which displays process information in a heirarchical fashion. It builds and runs on SLS linux, FreeBSD 4.4, FreeBSD 4.8, and MacOS 10.0.4. Unlike the standard pstree, it uses either sysctl() [macOS 10.0.4], kvm_getprocs() [FreeBSD 4.?] or /proc [SLS linux] as needed. PSTREE is free software; it is released under a BSD-style license that allows you to do as you wish with it as long as you don't attempt to claim it as your own work. To install pstree, do ./configure.sh (./configure.sh --help explains options) make make install (as root) If pstree needs to use sysctl() or kvm_getprocs() to read process information, it will be installed as a setuid process to allow it to read all of the process data.