  This volume contains the proceedings of the 8th International Workshop on
Quantum Physics and Logic (QPL 2011), which was held October 27-29, 2011 at
Radboud University Nijmegen. The goal of this workshop series is to bring
together researchers working on mathematical foundations of quantum physics,
quantum computing and spatio-temporal causal structures, and in particular
those that use logical tools, ordered algebraic and category-theoretic
structures, formal languages, semantic methods and other computer science
methods for the study of physical behavior in general. Over the past few years,
there has been growing activity in these foundational approaches, together with
a renewed interest in the foundations of quantum theory, which complement the
more mainstream research in quantum computation.
