precision machining is today an important increment to the optical fabrication repertoire; adding much, replacing little. through a historical survey and a discussion of machine design, we have tried to give a feel to the pace of development and the degree to which further developments may be anticipated. metrology, for example, has advanced to the level of a few atom layers. further dramatic increases in capability from metrology precision are unlikely, but developments from more sophisticated uses of metrology and servo-technology are surely possible. machine design, environmental control, and numerical control are being applied with increasing understanding and sophistication. tooling and machinability studies are in their infancy, in many cases waiting for third generation machines for sufficient control to sort out effects. polishing techniques are in a similarly primitive state. finally, we have attempted to point out that precision machining does not stand alone as a fabrication process, that successful applications will stem from the cooperative planning of optical designers, machine technologists, and optical finishers. (era citation 08:051862)