Near real time data analysis of at the INTEGRAL science data centre: a ten-year long rewarding effort.

The INTErnational  Gamma-Ray Astrophysics Laboratory (INTEGRAL) was 
selected by ESA on June 1993 as a medium size mission. For the first time,
a data centre (INTEGRAL Science Data Centre, ISDC) was developed externally 
to ESA and was considered of the same importance as a mission's instrument.
For more than 10 years, the ISDC has processed INTEGRAL telemetry, 
maintained the INTEGRAL archive accessible to the scientific community, and provided
a software for the data exploitation. Gamma Ray Bursts (GRB) 
and important astrophysical events, such as transient X-ray sources, 
were and continue to be detected in near real time and 
analysed by a scientist on duty. 
GRB alerts are automatically sent to registered clients to allow 
follow-up observations while other phenomena are published in Astronomer's Telegrams.

We review some of the most important discoveries obtained thanks to a 
prompt reaction to new or recurrent events in the 
hard X-ray sky (3-1000 keV). We estimate the reaction time, 
required man-power effort and staff competences, 
besides the infrastructure requirements to maximise the scientific return of those discoveries. 
The experience gained at the ISDC 
is also compared to similar monitoring efforts developed by other missions 
and put in context for future experiments.