This article provides a list of tools you can use to simulate load for your Web applications. By simulating load for your application, you can test concurrency issues as well as better understand how your application behaves under stress. Testing load and concurrency by refreshing a browser is not considered a valid test.

Use Microsoft Exchange Load Generator (LoadGen) as a simulation tool to measure the impact of MAPI clients on Exchange servers. LoadGen allows you to test how a server running Exchange responds to e-mail loads. To simulate the delivery of these messaging requests, you run LoadGen tests on client computers. These tests send multiple messaging requests to the Exchange server, thereby causing a mail load. LoadGen is a useful tool for administrators who are sizing servers and validating a deployment plan. Specifically, LoadGen helps you determine if each of your servers can handle the load to which they are intended to carry. Another use for LoadGen is to help validate the overall solution.

Spec Explorer is a software-development tool for advanced model-based specification and conformance testing. Spec Explorer can help software-development teams detect errors in the design, the specification, and the implementation of their systems. The tool is intended to be used by software testers, designers, and implementers.

PICT is an efficient way to design test cases and test configurations for software systems. With PICT, you can generate more effective test cases than you could reasonably hope to achieve manually, and in a fraction of the time that normal test case design consumes.

Building strong, reliable embedded devices is critical in today's market. Testing a device or driver can involve assessing many different elements from security, to usability, to performance. This is why Microsoft is working to provide the following tools and resources that will work in conjunction with your testing efforts.

Ever have a performance problem, but don't know what performance counters to collect or how to analyze them? The PAL (Performance Analysis of Logs) tool is a new and powerful tool that reads in a performance monitor counter log (any known format) and analyzes it using complex, but known thresholds (provided).