  In this contribution the current state of knowledge about the high-velocity
clouds (HVCs) is summarized. Recent progress has shown that the HVCs are a
diverse phenomenon. The intermediate-velocity clouds (IVCs) are likely to be
part of a Galactic Fountain. The Magellanic Stream is a tidal remnant. HVC
complex C (possibly complexes A and GCN) are low-metallicity clouds near the
Galaxy; they could be remnants of the formation of the Galaxy or old tidal
streams extracted from nearby dwarf galaxies. Having a substantial number of HI
HVCs dispersed throughout the Local Group seems incompatible with the observed
HI mass function of galaxies. Finally, FUSE finds high-velocity OVI, some of
which is clearly associated with HI HVCs, but some which is not.
