Back in September of last year, Oracle announced that it was working on merging its Java HotSpot Java Virtual Machine (JVM) and JRockit JVM. The plan was to take the best features of each implementation and combine them into a single JVM that would take the market by storm. Such a move not only required work in the realm of engineering, but also licensing. In a recent blog post by JRockit's program manager Henrik Stahl, he revealed that the work is finally complete, and the license under which the Oracle (Sun) JDK and JRockit are distributed has been updated. The new license is based on Sun's old Binary Code License that was tied to many Java downloads throughout the years, although it comes with some modifications of its own.
The major change with the license is that the JRockit JVM is now free for both internal use and development on general purpose computers. Kahl listed a couple of reasons for the conversion of JRockit to a free status in his blog post: “Since we are converging the JVMs technically it makes sense to treat them as a single "product" with two different incarnations/implementations. Second, by making JRockit free we hope to get more feedback on any regressions in the converged JVM vs current JRockit, which will help our convergence project.”
As far as commercial features are concerned, they will still require a commercial license. Examples of such features include JRockit Real Time, and JRockit Mission control, among others. Acquiring commercial licenses for the features has become a bit easier, as they can now be purchased one by one as needed for use with Java applications. Oracle will make any additional information concerning updated commercial offerings public as it becomes available, which includes support through a new and improved version of its Sun Java for Business program.
Kahl's blog post lists several key points that may come about regarding Oracle's latest move. First and foremost, JRockit can now be used with any Java application under the same terms that apply to the Oracle (Sun) JDK. As mentioned, it's also free. Any features that were previously free will remain that way to ensure accessibility. Oracle does not plan on making the current JRockit implementation open-source. Instead, the converged JVM will be accessible through OpenJDK. Developers are free to use JRockit Mission Control for free, as there is no charge for development use. JRockit Mission Control is available either as a standalone application or as a set of Eclipse plugins.
The JRockit download is available via the download page on the Oracle Technology Network, which can be found here: