A two-dimensional, zoomable, space filling user interface is presented for browsing conventional, hierarchical systems. Through user studies the Goldleaf browser was compared with the widely used Microsoft Windows Explorer user interface. The times and number of mouse clicks to locate directories and files were recorded. The user studies found that the Goldleaf browser required less than half the mouse clicks to locate a directory compared with Windows Explorer. Through the use of document thumbnails subjects were able to locate documents in less than two-thirds the time that it took using Windows Explorer. A majority of subjects felt that the ability of the Goldleaf browser to display multiple levels of the file system simultaneously was its most beneficial feature in completing the tasks. Subjects found that the Goldleaf browser required less mental and physical effort and was more enjoyable to use than Explorer.