What do you have to do to get "compatibility mode" in OpenGL?

Is a new coordinate system created with every transformation applied, e.g., translate or rotate?

What are "accumulation buffers"?

What happens in retained mode?

What is the purpose of calls to glLogicOp(GLenum opcode)?

What is the use of glOrtho?

Let us scale a striaght, horizontal line by a factor of 2 through using glScale(2.0f,0.0f,0.0f). This line consists of only 2 points, a left and right point. Which point(s) moves due to the scale transformation?

What are the native image formats supported by OpenGL?

What is "immediate mode"?