Bottom line: all the old OpenGL stuff still works.
Longer: I've reminded myself about OpenGL's versioning and backward compatibility. Back in late 2007, there was some controversy about a clean break with backward compatibility in OpenGL. Remember, OpenGL is much older than DirectX is, and so has many hoary old graphics features, for example immediate mode rendering. Turns out though these features are very nice as scaffolding for new students.
These features are one of the reasons that we're using OpenGL rather than DirectX this semester. DirectX has broken backward compatibility, requiring use of vertex buffers, shaders and more. This makes for a very steep learning curve.