I enhanced http://hpricot.com and deployed it to heroku.
I use hpricot.com to build and test various hpricot expressions and
then run them against a variety of websites.
Hpricot.com shows you the resulting html.
Also hpricot.com will render the resulting html.
For some development activities, hpricot.com is useful.
If you have any questions, e-me.