Femtosecond laser direct writing (FsLDW) has been established as a nano-enabler to solve problems that are otherwise not possible in diversified scientific and industrial fields, because of its unique three-dimensional processing capability, arbitrary-shape designability, and high fabricating accuracy up to tens of nanometers, far beyond the optical diffraction limit. We briefly review the underlying mechanisms for achievement of the superhigh fabrication spatial resolution and surface smoothness, and then discuss the rule and photochemical strategies that are currently exploited for FsLDW. Finally, applications of the delicate nanoprototyping approach in microelectronics, micromechanics, microoptics and microfluidics are introduced. (C) 2010 Elsevier Ltd. All rights reserved.