FlightGear: https://www.flightgear.org/
Mesa 3-D Libraries: https://www.mesa3d.org/
Search and Rescue: https://wolfpack.twu.net/SearchAndRescue/
The WINE Headquarters: https://www.winehq.com/
The XPilot Web Site: https://www.xpilot.org/
XScreenSaver Web Site: https://www.jwz.org/xscreensaver/
The XView Toolkit: https://step.polymtl.ca/~coyote/xview_main.html