  We review recent lattice QCD activities with emphasis on the impact on
nuclear physics. In particular, the progress toward the determination of
nuclear and baryonic forces (potentials) using Nambu-Bethe-Salpeter (NBS) wave
functions is presented. We discuss major challenges for multi-baryon systems on
the lattice: (i) signal to noise issue and (ii) computational cost issue. We
argue that the former issue can be avoided by extracting energy-independent
(non-local) potentials from time-dependent NBS wave functions without relying
on the ground state saturation, and the latter cost is drastically reduced by
developing a novel "unified contraction algorithm." The lattice QCD results for
nuclear forces, hyperon forces and three-nucleon forces are presented, and
physical insights are discussed. Comparison to results from the traditional
Luescher's method is given, and open issues to be resolved are addressed as
well.
