|  | Major changes from vwm2 include:
     - Introduction of integrated X client process and descendants
       monitoring in the form of per-window composited overlays.
       The rendering is done using the Composite, Damage, and Render
       extensions.  When the monitors are visible, vwm3 is a compositing
       manager.  When invisible, vwm3 continues to be an immediate-mode
       classic X11 minimalist window manager.
       Monitors are toggled via Mod1-;, Mod1-LeftArrow and Mod1-RightArrow
       may be used to decrease and increase the sampling frequency,
       respectively.  Mod1-' clears the monitored tasks history for the
       focused window when monitoring is visible.
       This feature depends on the CONFIG_CHECKPOINT_RESTORE kernel
       configuration option for the discovery of descendant processes.
       Without this kernel option enabled, you'll only get a single process
       monitored per window; the X client process as indicated by the
       _NET_WM_PID atom of the window.
       A library called libvmon has been introduced for the abstraction of
       lightweight system and process statistics sampling.
     Since vwm2 received backported features unrelated to monitoring or
     compositing while vwm3 was developed, there isn't really much
     difference between the two outside the monitoring context.
     This isn't to say there isn't much activity in the code, the addition
     of compositing and monitoring requires a substantial amount of code
     relative to the scale of vwm[12]. |