Profiling data visualization

Does anyone know how this is rendered:

http://blogs.oracle.com/realneel/resou开发者_如何学编程rce/open_table_hash_walk.svg

I really like this horizontal visualization of profiling data, where all the calls are instantly visible, rather than tree structure type of visualizations that you can find in most of the profilers.

I was wondering if the above image was rendered using some free or commercial script/component, or if anyone knows of similar visualization component.

The author is Neelakanth Nadgir, a former Sun engineer, and his blog page about the script is here.