For one of our projects, we wanted to do some load testing to validate if our infrastructure was sufficient. We decided not to use the Visual Studio Load testing features.
StresStimulus plays back HTTP requests recorded in Fiddler to create high concurrency workload on web applications. You can configure virtual users, think time, and number of test iterations or test duration.
After test completion, StresStimulus determines average performance of the test scenario. It breaks down response times of every page between server and network times to identify areas with scalability problems.
StresStimulus can be downloaded at http://stresstimulus.stimulustechnology.com. It is free, allows unlimited virtual users, and no registration is required.
Remark: When we tried to install the plugin on a 64bit machine, the installation failed. This is a known bug and the problem will be fixed in the next release. You can already download the alpha here.