compton [-d display] [-r radius] [-o opacity] [-l left-offset] [-t top-offset] [-i opacity] [-e opacity] [-cCfFSdG]
compton is a compositor based on Dana Jansens' version of xcompmgr (which itself was written by Keith Packard). It includes many improvements over the original xcompmgr, including window frame opacity, inactive window transparency, and shadows on argb windows.
Please report any you find to https://github.com/chjj/compton.
xcompmgr, originally written by Keith Packard, with contributions from Matthew Allum, Eric Anholt, Dan Doel, Thomas Luebking, Matthew Hawn, Ely Levy, Phil Blundell, and Carl Worth. Compton by Christopher Jeffrey, based on Dana Jansens' original work.