This week the IcedTea Project reached an important milestone - The latest OpenJDK binary included in Fedora 9 (x86 and x86_64) passes the rigorous Java Test Compatibility Kit (TCK). This means that it provides all the required Java APIs and behaves like any other Java SE 6 implementation - in keeping with the portability goal of the Java platform.Passing the TCK is generally considered a significant effort:
The Java TCK is a complex suite of tools and documentation that verifies that Java implementations conform to the Java specification. It consists of more than 80,000 tests and over 1 million lines of code.As discussed
The IcedTea project was created by the GNU Classpath team along with a handful of RedHat developers due to the need to replace all of the proprietary code with open source implementations. GNU Classpath provides many GPL-licensed replacements of the proprietary-licensed binary plugs still found in OpenJDK, making an IcedTea build of OpenJDK more-readily available for distributions on platforms such as Redhat's Fedora Linux distribution. Fedora 9 contains functionally complete OpenJDK packages, in part due to the contributions from IcedTea.Other open-source Java implementations, such as Apache Harmony, have been unable up to this point to pass the TCK, however not all of the difficulties have been related to technical issues. In April of 2007, the Apache Software Foundation sent an open letter to Sun Microsystems with the intent of solving key issues with licensing the TCK for testing against the Harmony platform; licensing issues that prevented the Harmony team from legally running the TCK in an open-source way. While Sun responded to the open letter, there has as-of-yet been no resolution of the licensing issues for the Harmony team, and they are still unable to run the TCK.
The IcedTea project is not subject to the same licensing issues as Apache Harmony, as Sun has provided a special version of the TCK license that is targeted to any Java implementation that is a derivative of OpenJDK; something that Apache Harmony cannot claim.
InfoQ will continue to report on the development of open-source Java implementations as new information becomes available.