I researched some on glass cooking ware. One of the few companies to make it was Corning Glass in New York State. My home state. It was popular. However, with the new "no stick" easier to clean, can't break it campaign. Many people switched to metal cookware. With so little a demand for the glass ware they stopped making it. They do currently manufacture Pyrex and Corning ware for baking. Seems no one wants to eat a cake out of metal though. Ever notice it taste different? I guess that is why grandma always used those baking cups when she made muffins. What did she know that we don't?
You can still purchase glass cookware at second hand places and via ebay.