  The French-Italian interferometric gravitational wave detector VIRGO is
currently being commissioned. Its principal instrument is a Michelson
interferometer with 3 km long optical cavities in the arms and a
power-recycling mirror. This paper gives an overview of the present status of
the system. We report on the presently attained sensitivity and the system's
performance during the recent commissioning runs.
  After a sequence of intermediate stages, the interferometer is now being used
in the so-called recombined configuration. The input laser beam is spatially
filtered by a 144 m long input mode-cleaner before being injected to the main
interferometer. The main optics are suspended from so-called \sa s, which
provide an excellent seismic isolation. The two 3 km long Fabry-Perot arm
cavities are kept in resonance with the laser light, and the Michelson
interferometer is held on the dark fringe. An automatic mirror alignment system
based on the Anderson technique has been implemented for the arm cavities. The
light leaving the dark port contains the gravitational wave signal; this light
is filtered by an output mode-cleaner before being detected by a photo
detector. This setup is the last step on the way to the final configuration,
which will include power recycling.
