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