this paper describes new developments in x-y stages for scanning or stepping and use in vacuum. the requirement for high dynamic stiffness is analyzed as to its effects on positioning accuracy in dynamically moving stages (scanning) and on settling time for stepping applications. novel solutions are described to increase the accuracy and stability of the x-y stages to perform in the nanometer range' (1) the use of piezoelectric locking systems to directly lock the product to the beam producing source (to reduce vibration to the subnanometer level), (2) through-the-chamber wall linear motor drives, where the x-y stages are located inside the vacuum chamber and linear motor drives are located outside the vacuum chamber, (3) the use of low friction ways with a mirror surface finish so that high smoothness and extremely constant velocity is achieved, and (4) how the combination of these new techniques has resulted in practical systems for nanometer fabrication and inspection