Beam is a Haskell interface to relational databases. Its key strengths are its type-safety and intuitive syntax. Beam is written in a pure Haskell, and doesn't make use of Template Haskell or non-intuitive embedded domain specific languages. Instead it makes extensive use of Generics, Closed Type Families, and other elements of Haskell's strong type system. Unlike other popular Haskell database interfaces, Beam tries to work with the compiler rather than in spite of it.
For more information, see http://travis.athougies.net/projects/beam.html