Microsoft LoadGen 2007 generates message transmission loads to run performance and stress tests for your Microsoft BizTalk Server applications, and provides performance counters to monitor the performance of the infrastructure running BizTalk Server.

This tool is intended for developers and IT professionals to simulate load on a BizTalk Server. Using this tool, you can simulate load to instrument performance and stress against a BizTalk deployment. In addition, this tool may also be extended by developers to simulate load for custom transports. This tool should be used in a test environment only, and should not be used in a production environment. This tool is provided “as-is” and is not supported.

Get it here.