This package provides macros to typeset some general mathematical operators (identity operator, trace, diagonal, rank, ...), a powerful implementation of the bra-ket notation (kets, bras, brakets, matrix elements etc. which can be sized as required), delimited expressions such as averages and norms, and some basic Lie algebra/group names. Macros for entropy measures for quantum information theory (smooth min- and max-entropy, smooth relative entropies, etc.) are also provided.