  A status report is given for the current theoretical understanding of pion
production close to threshold. In the first part of the talk predictions of a
meson exchange model are compared to recent polarized data for the reactions
$pp \to pp\pi^0$ as well as $pp\to pn\pi^+$ revealing, that the former reaction
is badly described whereas the predictions for the latter turn out to be
consistent with the data. Recent progress in the application of chiral
perturbation theory allows to understand this difference.
