A big problem with web application testing is that those who need the tools the most, such as independent site developers and departmental Web site managers, cant afford the five-figure price for most of these testing tools. Its hard to tell the boss you need $20,000 to test an application you said you could build yourself.

Of course, most Web application developers dont need many of the advanced features found in the commercial testing tools such as RadView Software Ltd.s WebLoad. They just want to see how their application handles certain loads. Fortunately, in this area, as in many others, open-source technology can provide a solution.

Several years ago, open-source testing software was usually limited to command-line tools that performed basic load tests against Web sites. Since then, there has been vast improvement, to the point where many tools now have simple-to-use, capable GUIs and can meet 90 percent or more of the needs of most application testers.

Two good open-source testing tools that eWEEK Labs has seen are Apache JMeter (at jakarta.apache.org/jmeter) and Dieseltest (at dieseltest.com).

The Java-based JMeter runs on any platform and enables surprisingly complex tests that get in-depth results. And while JMeter runs on top of Apache and Tomcat, it can be used to test any Web server or application server.

The Windows-based Dieseltest provides an intuitive GUI from which users can use a browser to record test scripts and quickly run tests that generated large loads.

The main weaknesses in these tools are their lack of advanced scripting options for testing complex applications and their often-limited reporting options.

But if you dont need advanced scripting or in-depth reports, these open-source testers can be effective.

More information about open-source testing tools can be found at opensourcetesting.org.