ETAPS 2003 was the sixth instance of the European Joint Conferences on T- ory and Practice of Software. ETAPS is an annual federated conference that was establishedin1998bycombininganumberofexistingandnewconferences.This yearitcomprised?veconferences(FOSSACS, FASE, ESOP, CC, TACAS),14- tellite workshops (AVIS, CMCS, COCV, FAMAS, Feyerabend, FICS, LDTA, RSKD, SC, TACoS, UniGra, USE, WITS and WOOD), eight invited lectures (not including those that are speci?c to the satellite events), and several tu- rials. We received a record number of submissions to the ?ve conferences this year: over 500,...