  Microlensing has proven to be a valuable tool to search for extrasolar
planets of Jovian- to Super-Earth-mass planets at orbits of a few AU. Since
planetary signals are of very short duration, an intense and continuous
monitoring is required. This is achieved by ground-based networks of telescopes
(PLANET/RoboNET, microFUN) following up targets, which are identified as
microlensing events by single dedicated telescopes (OGLE, MOA). Microlensing
has led to four already published detections of extrasolar planets, one of them
being OGLE-2005-BLG-390Lb, a planet of only ~5.5 M_earth orbiting its M-dwarf
host star at ~2.6 AU. Very recent observations (May--September 2007) provided
more planetary candidates, still under study, that will double the number of
detections. For non-planetary microlensing events observed from 1995 to 2006 we
compute detection efficiency diagrams, which can then be used to derive an
estimate of the Galactic abundance of cool planets in the mass regime from
Jupiters to Sub-Neptunes.
