  We present results from the first large-scale study of two flavor QCD using
domain wall fermions (DWF), a chirally symmetric fermion formulation which has
proven to be very effective in the quenched approximation. We work on lattices
of size 16^3x32, with a lattice cut-off of a^{-1}\approx 1.7 GeV, and dynamical
(or sea) quark masses in the range m_{strange}/2 \simle m_{sea} \simle
m_{strange}. After discussing the algorithmic and implementation issues
involved in simulating dynamical DWF, we report on the low-lying hadron
spectrum, decay constants, static quark potential, and the important kaon weak
matrix element describing indirect CP violation in the Standard Model, B_K. In
the latter case we include the effect of non-degenerate quark masses (m_s \neq
m_u = m_d), finding B_K(MS-bar, 2 GeV) = 0.495(18).
