Foreword of MEGA 2015

International audienceMEGA stands for Effective Methods in Algebraic Geometry, and its translations in various languages. It is a biennial series of conferences, which celebrated its 25th anniversary during the 2015 edition in Trento. Following the MEGA tradition, the conference was succeeded by a call for submissions to a standard issue of the Journal of Symbolic Computation on the occasion of MEGA 2015. Accepted contributors to the conference were encouraged to submit, but the call was open to everyone