  Nuclear-powered X-ray millisecond pulsars are the third type of millisecond
pulsars, which are powered by thermonuclear fusion processes. The corresponding
brightness oscillations, known as burst oscillations, are observed during some
thermonuclear X-ray bursts, when the burning and cooling accreted matter gives
rise to an azimuthally asymmetric brightness pattern on the surface of the
spinning neutron star. Apart from providing neutron star spin rates, this X-ray
timing feature can be a useful tool to probe the fundamental physics of neutron
star interior and surface. This chapter presents an overview of the relatively
new field of nuclear-powered X-ray millisecond pulsars.
