(OPEN Java Development Kit) The open source implementation of the Java Development Kit (see JDK). Introduced in 2006 by Sun, there were missing components because they were based on proprietary source code. In the following year, Red Hat launched "IcedTea," a project to make all software in OpenJDK compliant with the unrestricted GPL license (see GNU General Public License). In 2008, the entirely open source IcedTea6-based OpenJDK was made available with Red Hat's Fedora 9 distribution. See open source and Fedora.