Daison (DAta lISt comprehensiON) is an experiment to create a database which natively stores Haskell data types, instead of using the traditional SQL tables. The backend storage is SQLite from which I have stripped all SQL related features. The result is a simple key-value storage. On top of that there is a Haskell API which replaces the SQL language. For instance, Queries are simple list comprehensions generalized to a special monad.
For more details read the tutorial.