Multiple linked perspectives on hierarchical data.

This paper describes an interactive web-based tool for visualizing hierarchical data including the recently developed concept of space-reclaiming icicle plots and several more traditional hierarchy visualizations. The tool provides ways to upload, share, explore, and compare hierarchical data using a multitude of different linked hierarchy visualizations. The current version supports up to 8 hierarchy visualizations, with the space-reclaiming icicle plots among them. Several of the visualizations can be shown in linked views while typical hierarchy parameters and visual variables can be changed on user demand. The interactive tool makes use of OpenGL and Angular, an industry standard JavaScript platform, and runs in a web browser. We illustrate the usefulness of the visualization tool by applying it to the NCBI taxonomy that consists of more than 300,000 hierarchically organized species while filtering for the tetrapoda subhierarchy. Finally, we explain implementation details and discuss limitations and scalability issues of the linked visualization techniques.