What is 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, AJAX, Servlets, HTML Forms,
XML/SOAP Web Services, REST, 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 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.