 Each encumbrance was either released as free and open-source software or replaced with an alternative.Beginning in December 2010, all the so-called "binary plugs" were replaced by open-source replacements, making the whole JDK open sourced and the "binary plugs" not necessary anymore.On November 5, 2007, Red Hat announced an agreement with Sun, signing Sun's broad contributor agreement (which covers participation in all Sun-led free and open-source software projects by all Red Hat engineers) and Sun's OpenJDK Community Technology Compatibility Kit (TCK) License Agreement (which gives the company access to the test suite that determines whether a project based on OpenJDK complies with the Java SE 6 specification).