The Fifth International Conference on Reliable Software Technologies, Ada- Europe 2000, took place in Potsdam, Germany, June 26-30, 2000. It was - ganized by Ada Deutschland and sponsored by Ada-Europe, the European f- eration of national Ada societies, in cooperation with ACM SIGAda and the Gesellschaft fu ]r Informatik (GI). We gratefully acknowledge additional spons- ship by the DFG, the German Research Foundation, and by the Forschungsz- trum Karlsruhe. This year's conference marked the 20th anniversary of consecutive annual Ada-Europe conferences and the ?fth year of a conference focusing on the g- eral area of software reliability, in which Ada excels as one of the supporting technologies. The Y2K problem has put the importance of software reliability into the limelight of media and political attention. Luckily, the dire predictions about potentially disastrous failures of critical systems did not prove true at the turn of the year, most likely because an incredible e?ort was made to update existing software, modernize systems, check-out backup mechanisms, and so on. One cannot but wonder how much more reliable the software could have been if only apercentageofthefundsspentontheY2Kproblemhadgoneintoenhancements of reliability during the development and maintenance of the software."