  The International Gamma-Ray Astrophysics Laboratory (INTEGRAL) is dedicated
to the fine spectroscopy (Delta-E: 2 keV FWHM @ 1.3 MeV) and fine imaging
(angular resolution: 12 arcmin FWHM) of celestial gamma-ray sources in the
energy range 15 keV to 10 MeV with concurrent source monitoring in the X-ray (3
- 35 keV) and optical (V, 550 nm) range. The mission is conceived as an
observatory led by ESA with contributions from Russia and NASA. The INTEGRAL
observatory will provide to the science community at large an unprecedented
combination of imaging and spectroscopy over a wide range of energies. Most of
the observing time will be open to the scientific community. This paper
summarises the key scientific goals of the mission, the current development
status of the payload and spacecraft and it will give an overview of the
science ground segment including data centre, science operations and the key
elements of the observing programme
