Freeciv Web Site: https://www.freeciv.org/
GPS3D Visualization Tool: https://www.mgix.com/gps3d/
Mesa 3-D Libraries: https://www.mesa3d.org/
OpenGL: https://www.opengl.org/
TclTicker: https://www.nyx.net/~tpoindex/tcl.html#Tclticker
The WINE Headquarters: https://www.winehq.com/
XPlanet Web Site: https://xplanet.sourceforge.net/