  This note describes a \emph{Macaulay2} package for computations in prime
characteristic commutative algebra. This includes Frobenius powers and roots,
$p^{-e}$-linear and $p^{e}$-linear maps, singularities defined in terms of
these maps, different types of test ideals and modules, and ideals compatible
with a given $p^{-e}$-linear map.
