Boffins at the MIT Media Lab and MIT Glass Lab have found a way to print with glass extruded from a kiln at 1900ºC.
Glass 3D Printing (G3DP) uses a two chamber concept to heat and cool the glass before funnelling it via an alumina-zircon-silica nozzle into fully programmable shapes.
But never mind that. Just watch the glowing goo go.