Electron Beam Free-Form Fabrication (EBF3) is a rapid prototyping technology developed by Karen Taminger of NASA’s Langley Research Center. Dr. Taminger is prone to market EBF3 by analogy to Star Trek style “replicator” technology, which is nothing but shameless hype. Still, the basic idea is an interesting twist on extrusion-based 3D printing technologies (although there’s not really any “extrusion” going on), and is under development with an eye towards space-based fabrication. Working in outer space would eliminate the system’s major ground-based shortcoming, which is the requirement for maintaining a vacuum or inert atmosphere to prevent oxidation of the weld.