  For partially wetting, ellipsoidal colloids trapped at a fluid interface,
their effective, interface--mediated interactions of capillary and
fluctuation--induced type are analyzed. For contact angles different from
90$^o$, static interface deformations arise which lead to anisotropic capillary
forces that are substantial already for micrometer--sized particles. The
capillary problem is solved using an efficient perturbative treatment which
allows a fast determination of the capillary interaction for all distances
between and orientations of two particles. Besides static capillary forces,
fluctuation--induced forces caused by thermally excited capillary waves arise
at fluid interfaces. For the specific choice of a spatially fixed three--phase
contact line, the asymptotic behavior of the fluctuation--induced force is
determined analytically for both the close--distance and the long--distance
regime and compared to numerical solutions.
