th The 13 edition of the International Conference on Reliable Software Technologies (Ada-Europe 2008) marked its arrival in Italy by selecting the splendid venue of Venice. It did so after having been hosted twice in Switzerland, Spain and the UK (Montreux for its inauguration in 1996 and Geneva in 2007; Santander in 1999 and Palma de Mallorca in 2004; London in 1997 and York in 2005), and having visited Sweden (Uppsala, 1998), Germany (Potsdam, 2000), Belgium (Leuven, 2001), Austria (Vienna, 2002), France (Toulouse, 2003) and Portugal (Porto, 2006). It was certainly high time that the conference came to Italy! The conference series, which is run and sponsored by Ada-Europe, chooses its yearly venue following two driving criteria: to celebrate the activity of one of its national member societies in a particular country, and/or to facilitate the formation, or the growth, of a national community around all aspects of reliable software technologies. The success of this year's conference, beside the richness of its technical and social program, will thus be measured by its lasting effects. We can only hope that the latter will be as good and vast as the former! Owing to the absence of a national society associated with Ada-Europe in Italy, the organization of the conference was technically sustained by selected members of the Board of Ada-Europe, its governing body, with some invaluable local support.

Started on the inspired initiative of Prof. Alfred Strohmeier back in 1996, and spawned from the annual Ada-Europe conference that had previously run for 16 consecutive years, the International Conference on Reliable Software Technologies celebrated this year its tenth anniversary by going to York, UK, where the ?rst series of technical meetings on Ada were held in the 1970s. Besides being a beautiful and historical place in itself, York also hosts the Depa- ment of Computer Science of the local university, whose Real-Time Group has been tremendously in?uential in shaping the Ada language and in the progress on real-time computing worldwide. This year's conference was therefore put together under exc- lent auspices, in a very important year for the Ada community in view of the forthc- ing completion of the revision process that is upgrading the language standard to face the challenges of the new millennium. The conference took place on June 20-24, 2005. It was as usual sponsored by Ada-Europe, the European federation of national Ada societies, in cooperation with ACM SIGAda. The conference was organized by selected staff of the University of York teamed up with collaborators from various places in Europe, in what turned out to be a very effective instance of distributed collaborative processing. The conference also enjoyed the generous support of 11 industrial sponsors.

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.

This book constitutes the refereed proceedings of the 19th Ada-Europe International Conference on Reliable Software Technologies, Ada-Europe 2014, held in Paris, France, in June 2014. The revised 12 full papers presented together with two keynotes were carefully reviewed and selected from 68 submissions. They are organized in topical sections on formal methods; uses of ada; real-time scheduling; applications.