ACM Transactions on Programming Languages and Systems (TOPLAS) is the premier journal for reporting recent research advances in the areas of programming languages, and systems to assist the task of programming. Papers can be either theoretical or experimental in style, but in either case, they must contain innovative and novel content that advances the state of the art of programming languages and systems. We also invite strictly experimental papers that compare existing approaches, as well as tutorial and survey papers. The scope of TOPLAS includes, but is not limited to, the following subjects: language design for sequential and parallel programming programming language implementation programming language semantics compilers and interpreters runtime systems for program execution storage allocation and garbage collection languages and methods for writing program specifications languages and methods for secure and reliable programs testing and verification of programs