  A brief introduction to conventional DFT of 3D freezing is given and some
recent results are reviewed. The conventional DFT, however, can not be used in
the 2D case, particularly, because it can not describe the hexatic phase --
intermediate phase of 2D melting. We generalize DFT to describe 2D systems and
two-stage melting scenario including intermediate hexatic phase. Hexatic phase
is characterized by the appearance of bond orientational ordering. Our approach
describes this fact in terms of the appearance of nonisotropic part of the
two-particle distribution function while one-particle density remains constant.
Now we are dealing with the bifurcation of the solution of the equation for the
binary distribution function. Microscopic expressions for elastic moduli and
the Frank constant of hexatic phase are derived on the base of comparison of
distribution functions asymptotic behavior with the results of phenomenological
theories. We use our approach for the calculation of the phase boundary between
usual isotropic liquid and hexatic phase and slightly modified traditional DFT
for the phase boundary between hexatic phase and crystalline solid for a number
of 2D systems (hard disks, classical electron crystal, thin superconducting
films, Yukawa system etc.)
