Utilizing the jQuery widget factory and HTML5 canvas this Javascript treemap widget presents hierarchical data using the squarified treemap layout algorithm described in http://www.win.tue.nl/~vanwijk/stm.pdf, Squarified Treemaps, by Mark Bruls, Kees Huizing and Jarke J. van Wijk.  
Development and testing has primarily been limited to current versions of Chrome, Safari and FF.