GlassFish is dual licensed. How do I choose which license to use?
Anyone can download and use the GlassFish server under either the CDDL or GPLv2 + the Classpath exception software license. Where the licenses have effect is if you decide to distribute or modify the code. At the time you decide to distribute or modify the code, you have to choose a license. Once you make changes or distribute the code under your chosen license, all derivative works must be licensed in accordance with the terms of the license you choose.