  We describe ${\tt ipole}$, a new public ray-tracing code for covariant,
polarized radiative transport. The code extends the ${\tt ibothros}$ scheme for
covariant, unpolarized transport using two representations of the polarized
radiation field: in the coordinate frame, it parallel transports the coherency
tensor; in the frame of the plasma it evolves the Stokes parameters under
emission, absorption, and Faraday conversion. The transport step is implemented
to be as spacetime- and coordinate- independent as possible. The emission,
absorption, and Faraday conversion step is implemented using an analytic
solution to the polarized transport equation with constant coefficients. As a
result, ${\tt ipole}$ is stable, efficient, and produces a physically
reasonable solution even for a step with high optical depth and Faraday depth.
We show that the code matches analytic results in flat space, and that it
produces results that converge to those produced by Dexter's ${\tt grtrans}$
polarized transport code on a complicated model problem. We expect ${\tt
ipole}$ will mainly find applications in modeling Event Horizon Telescope
sources, but it may also be useful in other relativistic transport problems
such as modeling for the IXPE mission.
