Limits on compact halo objects as dark matter from gravitational
  microlensing
  Microlensing started with the seminal paper by Paczy\'nski in 1986, first
with observations towards the Large Magellanic Cloud and the galactic bulge.
Since then many other targets have been observed and new applications have been
found. In particular, it turned out to be a powerful method to detect planets
in our galaxy and even in the nearby M31. Here, we will present some results
obtained so far by microlensing without being, however, exhaustive.
