ECOOP 2015
Sun 5 - Fri 10 July 2015 Prague, Czech Republic
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Welcome to the 2nd Workshop on Programming Language Evolution

We are very pleased to confirm Bjarne Stroustrup will be our keynote speaker this year!

Programming languages tend to evolve in response to user needs, hardware advances, and research developments. Language evolution artefacts may include new compilers and interpreters or new language standards. Evolving programming languages is however challenging at various levels. Firstly, the impact on developers can be negative. For example, if two language versions are incompatible (e.g., Python 2 and 3) developers must choose to either co-evolve their codebase (which may be costly) or reject the new language version (which may have support implications). Secondly, evaluating a proposed language change is difficult; language designers often lack the infrastructure to assess the change. This may lead to older features remaining in future language versions to maintain backward compatibility, increasing the languageā€™s complexity (e.g., FORTRAN 77 to Fortran 90). Thirdly, new language features may interact badly with existing features, leading to unforeseen bugs and ambiguities (e.g., the addition of Java generics).

This workshop brings together researchers and developers to tackle the important challenges faced by programming language evolution, to share new ideas and insights, and to advance programming language design.

Topics include (but are not limited to):

  • Programming language and software co-evolution
  • Empirical studies and evidence-driven evolution
  • Language-version integration and interoperation
  • Historical retrospectives and experience reports
  • Tools and IDE support for source-code mining and refactoring/rejuvenation
  • Gradual feature introductions (e.g., optional type systems)

This year we are running PLE rather informally, with a number of contributed talks, discussion sessions, and a keynote. If you have any questions, or would like to submit a talk abstract (talks up to 30 minutes), please contact the program chairs at

We are proud to be supported by the Software Sustainability Institute

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Tue 7 Jul

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10:05 - 10:20
WelcomePLE at Hluboka II
Day opening
Dominic Orchard Imperial College London
10:20 - 11:10
Session 1PLE at Hluboka II
On the origin of the block concept
Gauthier van den Hove University of Amsterdam
Retrofitting static typing to Python
11:10 - 11:40
DiscussionPLE at Hluboka II

Call for Contributions

We are still accepting talk proposals (for 20-30 minute talks). If you are interested, please send a title+abstract to