The forthcoming data expected from space missions such as CoRoT require the
capacity of the available tools to provide accurate models whose numerical
precision is well above the expected observational errors. In order to secure
that these tools meet the specifications, a team has been established to test
and, when necessary, to improve the codes available in the community. The CoRoT
evolution and seismic tool activity (ESTA) has been set up with this mission.
Several groups have been involved. The present paper describes the motivation
and the organisation of this activity, providing the context and the basis for
the presentation of the results that have been achieved so far. This is not a
finished task as future even better data will continue to demand more precise
and complete tools for asteroseismology.Comment: 11 pages, 3 figures, accepted for publication in Astrophysics and
Space Science, 'CoRoT ESTA' special volum