Haskell cabal Taxonomy libary contains tools, parsers, datastructures and visualisation for the NCBI (National Center for Biotechnology Information) Taxonomy datasources.
It can utilize information from the Entrez REST interface (via EntrezHTTP, as well as from the files of the Taxonomy database dump.
Input data is parsed into a FGL based datastructure, which enables a wealth of processing steps like node distances, retrieval of parent nodes or extraction of subtrees.
Trees can be visualised via dot-format (graphviz) or via json-format (d3js).