This can be labeled as a significant achievement as the IcedTea project backed by RedHat coupled with OpenJDK has cleared the Java Test Compatibility Kit or TCK hence earning the tag of first open source Java implementation to clear it. Created by a team of GNU Classpath and RedHat developers IcedTea was aimed at replacing proprietary code with open source implementations.

It can be termed as an important feat to be accomplished as it offers all the Java APIs and functions like any other Java SE 6 implementation, after all it has emerged as a 100% GPL licensed Java implementation.