  Microlensing is the tool of choice for the search and the analysis of compact
halo objects ("MACHOs"), a still viable class of dark matter candidates at the
galactic scale. Different analyses point towards an agreement in excluding dark
matter MACHOs of less than about 0.1 solar mass; it remains however an ongoing
debate for values in the mass range (0.1-1) solar mass. The more robust
constraints, though not all in agreement, come from the observational campaigns
towards the Magellanic Clouds (the LMC and the SMC). The analyses towards the
nearby galaxy of M31, in the so called "pixel lensing" regime, have expanded
the perspectives in this field of research. In this contribution first we draw
a critical view on recent results and then we focus on the pixel lensing
analysis towards M31 of the PLAN collaboration.
