A Safety Concept for an IEC-61508 Compliant Fail-Safe Wind Power Mixed-Criticality System Based on Multicore and Partitioning -- The Central on-Board Computer of the Philae Lander in the Context of the Rosetta Space Mission.- Extensible Debugger Framework for Extensible Languages -- Static Backward Program Slicing for Safety-Critical Systems.- A Novel Run-Time Monitoring Architecture for Safe and Efficient Inline Monitoring.- Schedulability Analysis of PWM Tasks for the UPMSat-2 ADCS -- Guaranteeing Timing Requirements in the IXV on-Board Software.- Maintenance of Reliable Distributed Applications with Open-Source Middleware: Fifteen Years Later.- The CONCERTO Methodology for Model-Based Development of Avionics Software.- From AADL Model to LNT Specification.- Using Sensitivity Analysis to Facilitate the Maintenance of Safety Cases.- Challenges in the Implementation of MrsP -- An Execution Model for Fine-Grained Parallelism in Ada -- AFDX Emulator for an ARINC-Based Training Platform.

This book constitutes the refereed proceedings of the 20th Ada-Europe International Conference on Reliable Software Technologies, Ada-Europe 2015, held in Madrid, Spain, in June 2015. The revised 12 full papers presented together with two keynotes were carefully reviewed and selected from 36 submissions. They are organized in topical sections on language technology, real-time applications, critical systems, and multicore and distributed systems.