The previous recipe, PyGLet transforms our GUI easier than PyOpenGL, explains how to install PyGLet and gives you an introduction to this library. If you have not done so, it is probably a good idea to browse through that recipe.
In the online documentation, PyGLet is usually spelled in all lower-case. While this might be a Pythonic way, we capitalize the first letter of a class and we use lower case for variable, method, and function names to start each name.