In my Makefile I have the following:

objects = main.o Asteroid.o Bullet.o Projectile.o Ship.o
asteroids: $(objects)
g++ -o asteroids $(objects) -lX11 -lXi -lglut -lGL -lGLU -lm

I got the library switches from the OpenGL SuperBible. I was wondering what the -lXi switch is for because I tried the same program on my laptop and the -lXi switch is not recognized?