It was written rather more targeting the fixed-pipeline/rudimentary programmable shaders era. It's too bad it wasn't released a year or two later. That said, it is fairly well written and still has useful information relevant today, if occasionally a little sparse on the more advanced and fully relevant stuff (and I would say this book, plus the free online OpenGL 3.3 documentation plus an introduction to initiating the modern API, "Beginning OpenGL Game Programming - 2nd ed" make a much better set than getting the poor "OpenGL Programming Guide - 7th ed"; add "OpenGL Shading Language - 3rd ed" to these and and you are set).