The 20th International Conference on Reliable Software Technologies, Ada-Europe 2015, takes place on 22 - 26 June 2015 in Madrid, Spain. The conference provides an international forum for researchers, developers and users of reliable software technologies all over the world. Presentations and discussions cover applied and theoretical work currently conducted to support the development and maintenance of reliable software systems. David George from Rapita Systems will be presenting "Multi-Core Testing and Code Coverage". Stephen Law from CDS will be presenting "Effective Worst-Case Execution Time Analysis of DO-178C Level A Software", which was co-authored by Rapita Systems. Mark Pearce from Rapita Systems will be co-hosting a tutorial with other participants of the PROXIMA project. The tutorial will introduce atendees to Probabilistic Timing Analysis (PTA), and also Measurement-Based Probabilistic Timing Analysis. Come and meet Rapita Systems at the exhibition, where a demonstration of the latest version of RVS (v3.3) will be available. Further details of the conference can be found on the Ada-Europe website here: https://ae2015.dit.upm.es/index.html