The cost-shared project ECOSTAR (acronym for Ex-vessel Core Melt Stabilization Research) involves in total 17 organisations from five European countries and has been initiated on January 1, 2000 with a duration of 36 months. The objective of the project is to demonstrate the technical feasibility of core melt mitigation measures outside the reactor pressure vessel (RPV) as well as the validation of a selected set of codes in order to provide the necessary input for the definition of a convincing safety concept to control corium melts for both existing and future reactors. The ECOSTAR project is focussed on three key phenomena for ex-vessel mitigation measures namely melt release from RPV, ex-vessel corium transport and long-term corium stabilization. The extensive work programme covers different scenarios and consists of a large number of experiments with both simulant and real materials, code development and validation as well as analytical activities. This paper presents the progress of work and the results obtained from the launch of the project.