  Binary systems containing at least one radiopulsar are excellent laboratories
to test several aspects of fundamental physics like matter properties in
conditions of extreme density and theories of gravitation like the Einstein's
General Theory of Gravitation (GTR) along with modifications/extensions of it.
In this Chapter we focus on the perspectives on measuring the moment of inertia
of the double pulsar, its usefulness in testing some modified models of
gravity, and the possibility of using the mean anomaly as a further
post-Keplerian orbital parameter to probe GTR.
