PekWM is a highly configurable stacking window manager for the X Window System, written in C++ by Claes Nästen. The code is based on the aewm++ window manager, but it has evolved so that it no longer resembles aewm++. It also has an expanded feature-set, including window grouping (similar to Ion3, PWM, or Fluxbox), auto properties, xinerama and keygrabber that supports keychains, and much more.