ONTHEFRINGE (MSCF-CT-2005-029954) was a series of four schools designed to train young astronomers in optical interferometry. Optical interferometry is a new technology enabling observations with an angular resolution an order of magnitude larger than the largest single telescopes available at visible and infrared wavelengths. Optical interferometry is the only technology allowing the systematic direct detection and characterization of Earth-like planets orbiting other stars. Therefore it plays a key role in ESA s long-range plan through the Darwin mission, and in NASA s Origins program. On the ground, Europe has achieved world leadership with the ESO Very Large Telescope Interferometer (VLTI). Interferometry from the ground will play a central role in:

a) understanding the lifecycles of stars in the Milky Way,

b) the discovery and characterization of planets orbiting stars in the solar neighbourhood, and

c) the understanding of the energy conversion mechanisms in Active Galactic Nuclei.

The goal of the schools is to train a new generation of astronomers in the use of the VLTI, building critical mass in this emergent field, applying it to astrophysical areas of European leadership, optimizing the scientific use of the VLTI investment, overcoming fragmentation and uneven distribution of knowledge in optical interferometry in the European research area, therefore increasing European competitiveness in the scientific ground and space program enabled by optical interferometry. The schools consist in:

a) two data reduction schools were young astronomers will learn the essentials to become proficient users of the VLTI;

b) two thematic schools where optical interferometry is presented in context with other very high angular resolution techniques in key astrophysical areas of European leadership ( AGNs and Circumstellar disks and planets).

The program is supported by 15 EU member states, including new member states, and thus integrates the entire European optical interferometry community.