  Two classes of X-ray pulsars, the Anomalous X-ray Pulsars and the Soft
Gamma-ray Repeaters, have been recognized in the last decade as the most
promising candidates for being magnetars: isolated neutron stars powered by
magnetic energy. I review the observational properties of these objects,
focussing on the most recent results, and their interpretation in the magnetar
model. Alternative explanations, in particular those based on accretion from
residual disks, are also considered. The possible relations between these
sources and other classes of neutron stars and astrophysical objects are also
discussed.
