 Part of the class library (4%) could not be released as open source due to them being licensed from other parties and were included as binary plugs.Because of this, in June 2007, Red Hat launched IcedTea to resolve the encumbered components with the equivalents from GNU Classpath implementation.Since the release, most of the encumbrances have been solved, leaving only the audio engine code and colour management system (the latter is to be resolved using Little CMS).