A whole suite of strong gravitational lens phenomena have been investigated since the discovery of the first double quasar in 1979: multiple quasars, giant luminous arcs, quasar microlensing, galactic microlensing, Einstein rings, and extrasolar planets. Today strong lensing is a booming part of astrophysics and cosmology, covering more than 20 orders of magnitude in mass. A number of recent applications will be presented and discussed, including lensing results on the physics of quasars, lensing constraints on dark matter in galaxies, and lensing discoveries oflow-mass exoplanets.

Joachim Wambsganss