This talk will cover two distinctly different mechanically hard films. The first is a dual reactive magnetron sputtered mulilayer consisting of alternating polycrystalline TiN and amorphous SiNx layers. The TiN layers exhibit a preferred 200 orientation for layer thicknesses below 10 nm. For thicker layers 111 orientations are also observed. The amorphous SiNx layers provides for TiN renulcleation in each layer yielding a column free microstructure. Nanoindentation was used to evaluate the hardness which varied between 18 to 32 GPa depending on the layer modulation. For large wavelength (>20 nm), Hall-Petch dependence is observed with a generalized power of -0.4. For shorter wavelengths superhardening yields a deviation from the Hall-Petch relationship. The highest hardness is observed for mulilayers having thin SiNx -layers (< 1nm) for which HRTEM reveals a transformation from amorphous to crystalline SiNx layers growing cube on cube on the TiN crystals. The formation of crystalline SiNx and its influence on hardening is discussed. The second material system to be reviewed is arc evaporated Ti1-xAlxN with a range of compositions (x=0 to 0.74). As-deposited coatings with xï,£0.66 had metastable cubic structures. Annealing at 1100 °C of these films resulted in phase separation of c-TiN and h-AlN, via spinodal decomposition of c-TiN and c-AlN. The high hardness (~37 GPa) and texture of the Ti1-xAlxN coatings are retained for annealing temperatures up to 950ï,°C, which indicates a superior stability of this system compared to TiN and Ti(C,N) coatings. It is proposed that competing mechanisms are responsible for the effectively constant hardness; softening by lattice defect annihilation is balanced by hardening from formation of a nano-composite structure of c-AlN volumes by spinodal decomposition.