Quipper is a high-level functional programming language for quantum computing that was designed and implemented at Dalhousie University and the University of Pennsylvania a few years ago. The language is practical and scalable - seven non-trivial algorithms from the quantum computing literature have already been implemented in it. But Quipper, which is implemented as an embedded language, lacks theoretical foundations and a model. In this talk, I will present a Quipper-like language with a solid theoretical foundation and a compositional denotational semantics.  This is joint work with Francisco Rios.