OpenJDK Regression Test Harness, also known as jtreg, now available as open source
Go to openjdk.java.net and scroll your eyes down to the Tools section of the navigation bar. You will see a link that's been there a long time, jtreg harness. There is new stuff behind that link now available. Today we have made this harness open source under the GPL+Classpath license combo. (Jonathan Gibbons' announcement)
The OpenJDK Regression Test Harness, also known as jtreg, is the test harness used in the OpenJDK for running unit and regression tests. Jtreg is a wrapper around JT Harness which simplifies its use. Documentation is on the jtreg harness home page.
How is this important? Previously jtreg had been available under the most liberal closed source binary license you could imagine. The license said you can do essentially anything you want with the binary jtreg distribution. No matter how liberal that binary license, it interfered with the ability of some Linux distros to make use of the unit and regression tests. I wish to thank the project members of these Linux distros for explaining the importance and distinction between the most liberal binary license you can imagine and a proper open source license. Once I groked the distinction it deepened my understanding of the open source culture.
In the end what is important is that OpenJDK builds are as high quality as possible. Enabling the distro's to run the unit and regression tests help them have comfort in knowing the tests passed.