  Astrophysical jets exist from the stellar scale up to AGN, and seem to share
common features particularly in the radio. But while AGN jets are known to emit
X-rays, the situation for XRB jets is not so clear. Radio jets have been
resolved in several XRBs in the low/hard state, and it seems likely that some
form of outflow is present whenever this state is achieved. Interestingly, the
flat-to-inverted radio synchrotron emission associated with these outflows
strongly correlates with the X-ray emission in several sources, suggesting that
the jet plasma plays a role at higher frequencies. In this same state, there is
also increasing evidence for a turnover in the IR/optical where the
flat-to-inverted spectrum seems to connect to an optically thin component
extending into the X-rays. We discuss how jet synchrotron emission is likely to
contribute to the X-rays, in addition to inverse Compton up-scattering,
providing a natural explanation for these correlations and the turnover in the
IR/optical band.
