  This is a review article on modular categories, extending an invited talk
given at the workshop "Categorical (co)algebraic methods in quantum informatics
and linguistics", Oxford, October 29-31, 2010. To appear in C. Heunen, M.
Sadrzadeh, E. Grefenstette (eds.): Compositional methods in quantum physics and
linguistics, Oxford University Press, 2012.
