I've used JMeter (http://jakarta.apache.org/jmeter/ http://jakarta.apache.org/jmeter/) for a few years now. It's easy to use and extend. The only thing I don't

I've used JMeter (http://jakarta.apache.org/jmeter/ http://jakarta.apache.org/jmeter/) for a few years now. It's easy to use and extend. The only thing I don't like is it doesn't play nice with AJAX.