Free Tools to Load/Stress Test Your Web Applications

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I've been looking at SLAMD lately - http://www.slamd.com/. It's also distributed and can be controlled largely by a built in web interface. With many of the other distributed tools (JMeter, The Grinder) you have to muck around with the Java desktop app which is less than intuitive.

Chris Groskopf of the Chicago Tribune News Apps team just released Bees with Machine Guns (http://blog.apps.chicagotribune.com/2010/07/08/bees-with-mac...), which looks like a lot of fun.