WebInject

WebInject is a free tool for automated testing of web applications and web
services. It can be used to test individual system components that have HTTP
interfaces (JSP, ASP, CGI, PHP, Servlets, HTML Forms, XML/SOAP Web Services,
etc), and can be used as a test harness to create a suite of [HTTP level]
automated functional, acceptance, and regression tests. A test harness, also
referred to as a test driver or a test framework, allows you to run many
test cases and collect/report your results. WebInject offers real-time
results display and may also be used for monitoring system response times.

WebInject can be used as a complete test framework that is controlled by the
WebInject User Interface (GUI). Optionally, it can be used as a standalone
test runner (text/console application) which can be integrated and called
from other test frameworks or applications.

WWW: http://www.webinject.org/