  After recalling the conceptual foundations and the basic structure of general
relativity, we review some of its main modern developments (apart from
cosmology) : (i) the post-Newtonian limit and weak-field tests in the solar
system, (ii) strong gravitational fields and black holes, (iii) strong-field
and radiative tests in binary pulsar observations, (iv) gravitational waves,
(v) general relativity and quantum theory.
