Miller is like sed, awk, cut, join, and sort for name-indexed data such as CSV. With Miller, you get to use named fields without needing to count positional indices. This is something the Unix toolkit always could have done, and arguably always should have done. It operates on key-value-pair data while the familiar Unix tools operate on integer-indexed fields: if the natural data structure for the latter is the array, then Miller's natural data structure is the insertion-ordered hash map. This encompasses a variety of data formats, including but not limited to the familiar CSV. (Miller can handle positionally-indexed data as a special case.)