Compton is a compositor for X11, which was forked from Dana Jansens' fork
of xcompmgr, and heavily refactored.

Most prominent changes from the original xcompmgr:

  - OpenGL/GLX backend in addition to the old XRender backend
  - Inactive window transparency and dimming
  - Titlebar/frame and menu transparency
  - Shadows for ARGB windows, e.g. terminals with transparency
  - Colored shadows; new fade system
  - Blur of background of transparent windows, window color inversion
  - Configuration file support with blacklisting

WWW: https://github.com/chjj/compton