  A manifestly Lorentz invariant action is found for the Floreanini-Jackiw
chiral boson. The method involves a novel chiral reduction of the phase-space
action for a string, and can be adapted to describe chiral bosons on the
heterotic string worldsheet. A similar manifestly Lorentz invariant action is
found for an entire class of conformal chiral 2k-form electrodynamics in (4k+2)
dimensions which includes the Floreanini-Jackiw theory as the k=0$ case.
