FlightCraft3D
realistic but simple flight simulator: exploration and casual landing
... also a non-GL version that displays whole 3D gfx with a procedure at whose end pixels are displayed with SDL, asciiart, of native Linux X11 graphics of native Win graphics. Ofc ourse OpenGL is very useful for displaying nice trees... .
it's a single sourcefile program.
USAGE: in any Linux/UNIX system (es.Ubuntu) download the zip and place it in your home directory; extract the zip. open a Terminal and navigate int the folder of the game;type this: "make";press ENTER; double-click the a.out