* Screensavers can't launch setuid / sergid executables like gfx_switcher
* Screensavers can't launch executables downloaded from Internet unless vetted by user vis GateKeeper
* Apple's ScreenSaverEngine doesn't always call stopAnimation before exiting
* Apple's ScreenSaverEngine always passes true for isPreview argument
* OpenGL apps built under Xcode 11 & Catalina use window doubled window dimensions on Retina displays (2 pixels per point)
* The CGWindowList method we have used to display project graphics apps which have not been updated no longer works
* Screensaver output files are put in an obscure sandboxed directory