Stella

Stella is a handy web application testing tool developed by Solutious Inc, a small software company based in Montreal. Stella is a very lightweight Ruby test tool for functional and performance testing. Like JMeter, Stella doesn't simulate a browser; it generates HTTP requests and parses the responses. Currently, Stella provides support for automatic parsing of HTML, XML, XHTML, YAML and JSON.

A few months ago, I wrote an introductory article on Stella for SearchSoftwareQuality.com - you can find it here.