This is not such a great article. It's true that the meme "glass is a liquid" is tiresome and incorrect, and it is true that glass doesn't flow at usual temperatures, but glass is very special and interesting because it doesn't undergo a state transition from liquid to solid state. So in a very specific technical sense, glass can be considered liquid, but there are many definitions of liquid and solids and this one doesn't align with people's naive definition.
I hoped would article would touch these special properties of glass.
http://en.wikipedia.org/wiki/Glass#Formation_from_a_supercoo...