21St European Symposium on Programming (Esop) Held as Part of the 15Th European Joint Conferences on Theory and Practice of Software (Etaps), Date: MAR 24-APR 01, 2012, Location: Tallinn, ESTONIA, Sponsors: Tallinn Univ Technol, Inst Cybernet, European Assoc Theoret Comp Sci (EATCS), European Assoc Programming Languages & Syst (EAPLS), European Assoc Software Sci & Technol (EASST), Estonian Ctr Excellence Comp Sci (EXCS), Estonian Convent Bur, Microsoft Res, Host: Tallinn Univ Technol (TUT)