  In May 1997 a consistent part of the services and structures committed to the
industry had already been released to the commissioning group. The telescope
itself was, with the exception of the Nasmyth derotators, motors and all the
optics groups, basically ready in its mechanical parts to accept the
integration of all services and control equipment. Also the verification of the
cabling (interlocks, data-nets, power and controls) already mounted was started
in the same period. Starting from June 1998 (telescope first-light date) the
telescope went gradually in use, several nights per week, in order to test and
tune the tracking and pointing system, the optics and the first derotator
system (Nasmyth A station). At the end of the commissioning period and with the
first scientific instruments mounted (April 1999) also the first routinely
observations started. In this moment the telescope is doing astronomy 80% of
time and the complete first-light instrumentation is mounted.
