IcedTea

IcedTea is a build and integration project for OpenJDK launched by Red Hat in June 2007.

This goal was met, and a version of IcedTea based on OpenJDK was packaged with Fedora 8 in November 2007.

April 2008 saw the first release[5] of a new variant, IcedTea6, which is based on Sun's build drops of OpenJDK6, a fork of the OpenJDK with the goal of being compatible with the existing JDK6.

However, parts of the class library, such as font rendering, colour management and sound support, were only provided as proprietary binary plugins.

The team could not call their software product "OpenJDK" because this is a trademark which was owned by Sun Microsystems.

[14] On November 5, 2007, Red Hat signed both the Sun Contributor Agreement and the OpenJDK Community Technology Compatibility Kit (TCK) License.

[19][20] In June 2008, it was announced that IcedTea6 (as the packaged version of OpenJDK on Fedora 9) has passed the (TCK) tests and can claim to be a fully compatible Java 6 implementation.

[31] As of April 2013, Oracle has kept the codebase of the Java plugin fully proprietary,[32] in contrast to the remainder of OpenJDK.

The integration project is a cooperation between the AdoptOpenJDK community, Red Hat, and Karakun AG.

From June 2007, IcedTea was able to build itself and pass a significant portion of Mauve, the GNU Classpath test suite.

Currently (as of April 2012): OpenJDK contained approximately (on release in May 2007) 4% encumbered code,[14] which was only packaged as binary plugins.

Cross-architecture ports of HotSpot (OpenJDK's Virtual Machine) are difficult, because the code contains much assembly language, in addition to the C++ core.

[48][49] This port is intended to allow the interpreter part of HotSpot to be very easily adapted to any Linux processor architecture.

[51][52][53] The IcedTea project has also developed a platform-independent just-in-time compiler called Shark for HotSpot, using LLVM, to complement Zero.