Fabric3 is licensed under the GNU Public License v3 with the GNU Classpath Exception clause. This means there are no licensing requirements placed on applications which run on Fabric3 - they can be open source or proprietary.
However, modifications to Fabric3 such as enhancements or extensions must be distributed under the GPL v3 (the Classpath Exception is optional). In addition, runtimes which embed Fabric3 must be distributed under the GPL v3.
Other licensing terms are available by mutual agreement.
Fabric3 is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version, with the following exception:
Linking this software statically or dynamically with other modules is making a combined work based on this software. Thus, the terms and conditions of the GNU General Public License cover the whole combination.
As a special exception, the copyright holders of this software give you permission to link this software with independent modules to produce an executable, regardless of the license terms of these independent modules, and to copy and distribute the resulting executable under terms of your choice, provided that you also meet, for each linked independent module, the terms and conditions of the license of that module. An independent module is a module which is not derived from or based on this software. If you modify this software, you may extend this exception to your version of the software, but you are not obligated to do so. If you do not wish to do so, delete this exception statement from your version.
Fabric3 is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
A copy of the GNU General Public License can be obtained from: http://www.gnu.org/licenses.