http://www.falloutsoftware.com/tutorials/gl/gl0.htm
http://www.morrowland.com/apron/tut_gl.php
http://fly.cc.fer.hr/~unreal/theredbook/chapter03.html
http://www.opengl-tutorial.org/beginners-tutorials/tutorial-3-matrices/
http://www.opengl.org/wiki/GluLookAt_code
http://www.songho.ca/opengl/gl_transform.html
http://www.songho.ca/opengl/gl_transform.html#modelview
http://www.videotutorialsrock.com/index.php
http://www.songho.ca/opengl/gl_projectionmatrix.html

http://content.gpwiki.org/index.php/SDL:Tutorials:Using_SDL_with_OpenGL
http://content.gpwiki.org/index.php/SDL_ttf:Tutorials:Fonts_in_OpenGL
http://pyopengl.sourceforge.net/documentation/manual/glutBitmapCharacter.3GLUT.html
http://db-in.com/blog/2011/02/all-about-opengl-es-2-x-part-23/
http://lazyfoo.net/SDL_tutorials/lesson36/index.php