The techniques of lattice field theory, combined with advances in high performance computing now allow many important questions
which involve the physics of quarks and gluons to be answered
using numerical methods. Formulations of fermions appropriate for
this numerical work which also respect the independent symmetry
of the right- and left-handed quarks extend the range of phenomena
which can be accurately treated using lattice QCD. These chiral
fermion techniques will be reviewed and recent applications to
the calculation of weak decay amplitudes presented.