. Data fields provide a flexible and highly general model for indexed collections of data. Data Field Haskell is a Haskell dialect that provides an instance of data fields. It can be used for very generic collection-oriented programming, with a special emphasis on multidimensional structures. We give a brief description of the data field model and its underlying theory. We then describe Data Field Haskell, and an implementation. 1 Introduction Indexed data structures are important in many computing applications. The canonical indexed data structure is the array, but other indexed structures like hash tables and explicitly parallel entities are also common. In many applications the indexing capability provides an important part of the model: when solving partial differential equations, for instance, the index is often closely related to a physical coordinate, and explicitly parallel algorithms often use processor ID's as indices. Since the time of APL [5] it has been recognised ...