  Radio-loud neutron stars known as pulsars allow a wide range of experimental
tests for fundamental physics, ranging from the study of super-dense matter to
tests of general relativity and its alternatives. As a result, pulsars provide
strong-field tests of gravity, they allow for the direct detection of
gravitational waves in a 'pulsar timing array', and they promise the future
study of black hole properties. This contribution gives an overview of the
on-going experiments and recent results.
