Progress in kaon physics on the lattice

We review recent progress in calculating kaon spectrum, pseudoscalar meson decay constants, $B_K$, $\epsilon'/\epsilon$, $K\to \pi\pi$ matrix elements, kaon semileptonic form factors, and moments of kaon distribution amplitudes on the lattice. We also address the issue of how best to improve the staggered fermion formulation for the action and operators.