This is the errors with including JUST spacejunk.c gcc -o schprel schprel.c -O -DMAC_OS_X -I/usr/include/sys -I/System/Library/Frameworks/GLUT.framework/Versions/A/Headers -I/System/Library/Frameworks/OpenGL.framework/Versions/A/Headers -O -L/usr/local/lib -L/System/Library/Frameworks/OpenGL.framework/Libraries -lGL -lGLU -lobjc -lm -framework GLUT In file included from schprel.c:309: spacejunk.c:399: error: redefinition of `drawSelf' self.c:151: error: `drawSelf' previously defined here spacejunk.c:767: error: redefinition of `updateSelf' self.c:185: error: `updateSelf' previously defined here make: *** [schprel] Error 1