Welcome to the proceedings of ECOOP 2009! Thanks to the local organizersfor working hard on arranging the conference — with the hard work they put in, it was a great success. Thanks to Sophia Drossopoulou for her dedicated work as PC Chair in assembling a ?ne scienti?c program including forward-looking keynotes, and for her e?orts to reduce the environmental impact of the PC meeting by replacing a physical meeting with a virtual meeting. I would also like to thank James Noble for taking the time and e?ort to write up last year’s banquet speech so that it could be included in this year’s proceedings. One of the strong features of ECOOPis the two days of workshopspreceding themainconferencethatallowsintenseinteractionbetweenparticipants.Thanks to all workshop organizers. Lastyear’ssuccessfulsummerschooltutorialswerefollowedupthisyearwith seven interesting tutorials. Thanks to the organizers and speakers. This year’s Dahl-Nygaard award honored yet another pioneer in the ?eld, namely, David Ungar for his contributions includingSelf. I appreciate his e?orts in providing us with an excellent award talk. The world is changing and so is ECOOP. Please contemplate my short note on the following pages entitled On Future Trends for ECOOP.

This book constitutes the refereed proceedings of the 25th European Conference on Object-Oriented Programming, ECOOP 2011, held in Lancaster, UK, in July 2011. The 26 revised full papers, presented together with three keynote lectures were carefully reviewed and selected from a total of 100 submissions. The papers cover topics such as empirical studies, mining, understanding, recommending, modularity, modelling and refactoring, aliasing and ownership; as well as memory optimizations.

This book constitutes the proceedings of the 27th European Conference on Object-Oriented Programming, ECOOP 2013, held in Montpellier, France, in July 2013. The 29 papers presented in this volume were carefully reviewed and selected from 116 submissions. They are organized in topical sections on aspects, components, and modularity; types; language design; concurrency, parallelism, and distribution; analysis and verification; modelling and refactoring; testing, profiling, and empirical studies; and implementation.

This book constitutes the refereed proceedings of the 26th European Conference on Object-Oriented Programming, ECOOP 2012, held in Beijing, China, in June 2012. The 27 revised full papers presented together with two keynote lectures were carefully reviewed and selected from a total of 140 submissions. The papers are organized in topical sections on extensibility, language evaluation, ownership and initialisation, language features, special-purpose analyses, javascript, hardcore theory, modularity, updates and interference, general-purpose analyses.

This book constitutes the proceedings of the 28th European Conference on Object-Oriented Programming, ECOOP 2014, held in Uppsala, Sweden, in July/August 2014. The 27 papers presented in this volume were carefully reviewed and selected from 101 submissions. They are organized in topical sections named: analysis; design; concurrency; types; implementation; refactoring; JavaScript, PHP and frameworks; and parallelism.

This book constitutes the refereed proceedings of the 24th European Conference on Object-Oriented Programming, ECOOP 2010, held in Maribor, Slovenia, in June 2010. The 24 revised full papers, presented together with one extended abstract were carefully reviewed and selected from a total of 108 submissions. The papers cover topics such as programming environments and tools, theoretical foundations of programming languages, formal methods, concurrency models in Java, empirical methods, type systems, language design and implementation, concurrency abstractions and experiences.

This book presents a survey of the state-of-the-art on techniques for dealing with aliasing in object-oriented programming. It marks the 20th anniversary of the paper The Geneva Convention On The Treatment of Object Aliasing by John Hogg, Doug Lea, Alan Wills, Dennis de Champeaux and Richard Holt. The 22 revised papers were carefully reviewed to ensure the highest quality.The contributions are organized in topical sections on the Geneva convention, ownership, concurrency, alias analysis, controlling effects, verification, programming languages, and visions.